Semax is likely "associative", as far as I'm aware it's an NMDA agonist. I know you said Selank, but Semax is the closest thing I could think of, off the top of my head. I can't figure out exactly what it does as far as NMDA receptors so I'll just quote a study I found while trying:
Predominance of Nootropic or Anxiolytic Effects of Selank, Semax, and Noopept Peptides Depending on the Route of Administration to BALB/c and С57BL/6 Mice
It's behind a paywall but this is just in the abstract:
In BALB/c mice, i.p. administration of noopept and i.n. administration of selank increased the density of NMDA-receptors in the hippocampus and i.n. administration of noopept and semax reduced their density, with no effect on mGluII-receptors.
So... make of that what you will, maybe it's worth a shot. It's strange because both noopept, semax, and selank in my experience are anti-dissociative, as in, they are essentially dissociative antidotes capable of rapidly returning one from close to K-hole to pretty much fully associated normality - if with some residual mental scatteredness - they are almost completely curative of distorted perception, movement, probably anaesthesia, and any majorly significant cognitive distortions (this is true, at least, of the less weird dissociatives, more sedating ones that are closer to ketamine in effect - the curative effect is less surprisingly acute with some of the weirder ones, the PCP analogues and such).
Both noopept and selank I find to be anxiolytic despite this though, so I guess it could be simply that they both have higher affinities for NMDAr that the majority of known dissociatives, whereas their actual action on those receptors varies. So yeah, selank is worth a short. Noopept too, I'd say - although the latter can definitely be brainfoggy, and the anxiolysis can take a while to fully manifest (maybe 7-10 days of 3x daily dosing, IME). I have less experience with Selank - it definitely could be brainfoggy too but the anxiolytic effect is more immediate, I think, and maybe longer lasting, possibly also more sustainable as noopept the advice is to take breaks every 40 days or so, but, this is almost pure conjecture now, neither is well studied and my own experience is limited and hasn't involved particularly rigorous self-analysis... somewhat to my own frustration with myself.
You might also try memantine - it is essentially a dissociative but in low doses not functionally impairing, many people advise building up gradually from, say, 2.5mg a day to 10, 20 or even 40mg depending on, I guess, how far you feel you need to go. The point of building up gradually is to avoid any significant impairment as your brain can gradually acclimatise to it - but it can possibly cause a slight reduction in intellectual capacity, maybe brainfog also - at least this was my perception - again, not a rigorously examined one - and possibly a result of tapering upwards too quickly, or just giving up too early out of impatience. It is an interesting substance though, likely very safe for long term use, and with some glowing anecdotal reports of people taking it for similar reasons to you.
On the milder end of things, as far as what you could probably buy in any random health shop - some form of highly bioavailable magnesium - chelated magnesium glycinate, off the top of my head, I think is one of the best - would be mildly NMDA-antagonising and, therefore, perhaps, mildly dissociative... many people report it to help with sleep, to be somewhat calming... as a pretty seasoned dissociative user I personally do not find it to be anything special or even, really, noticeable, although I still keep some around, and YMMV.
There's also l-theanine, an anxiolytic amino acid for which the body seems to have no homeostatic mechanism by which to develop tolerance to it or reduce it's effectiveness. I'm unsure where it falls on the scale of functional dissociation, but... it definitely is effective, if mild, and seems to be something that can be used long term.
I would definitely stay away from opiates, even kratom, that is not sustainable and will wreck your baseline state of mind the longer you take it, leading you to feel worse in a way that opiates can no longer correct. Same goes, honestly, for most "proper" dissociatives themselves - unfortunately - definitely DXM, not surprising that stopped worked. These substances are all just far too powerful, blunt instruments with a broad spectrum of effects, not all of them desirable, and that your brain can and will compensate for fairly quickly in ways that are not going to be desirable to you either.
Magnesium, l-theanine, selank, memantine, maybe noopept... definitely those ones I'd give a shot. I listed them roughly in the order that I would attempt them even though I don't think magnesium will do much for you if I'm honest, and noopept I didn't rank last because I think it's most effective, just because I'm less certain about how sustainable it is or how reliable the anxiolytic effects are, as well as the variability in reported possible side effects (brainfog maybe as I mentioned - I just remembered also that I experienced significant loss of libido while I was taking it which resolved within days of quitting).
EDIT: I'll just add also... I actually really understand what you mean and identify with it, being too "associated" is something I struggle with, presently, and for some time. I don't socialise with dissociatives because I find it to be too risky, I am apparently not so great at walking the line between threshold functionality and obvious impairment, but I am strongly drawn to them for their power to simply switch off the emotions that I don't fully understand and find it exhausting to deal with. Unfortunately I have abused them and despite that pull that still remains they are nowhere near as reliable as relief as they once were, and quite often have a depressive effects in the days to even weeks after, and while I still, much to my own frustration with myself, have not entirely cut out ketamine - I am working on it and my use is more and more infrequent, ideally it'll gradually asymptote to zero.
My attention span is currently almost nonexistent and my desire to socialise is equally pretty much in the toilet. I have an absurd need for alone time for no particular reason - very much resonated with me that you said even your girlfriend triggers you from time to time - I observe the same thing in myself. It is particularly difficult because it's so hard to explain, it's not anything she's doing - I just can't handle spending too long with
anyone, right now. I've attempted to medicate my inability to care about almost anything and my pathological social avoidance with both stimulants (primarily modafinil, but amphetamine at peak dysfunction) and opiates (tianeptine, kratom - the latter of which is far, far less sustainable - tianeptine I found much more forgiving) but the effectiveness of all of these things waned to the point the side effects were more trouble to deal with than what I was trying to treat. The resultant anxiety from this maddening cycle as well as, just, life, I guess, my default emotional state, I've tried to medicate with GABAergics, phenibut, benzos... this was equally and predictably unsustainable. I'm currently abstinent from pretty much everything except the odd minor K binge every month or so and if I'm honest the odd few days of some kind of benzo or a stimulant thrown in when my frustration at my own psychological inertia gets too much. Honestly I'm kinda jaded about everything right now, but, probably I'll have another go with some of the things I've recommended to you at one point.
Stimulants - while they are helpful for treating some of my symptoms - inevitably make me crave dissociatives on the fade. The association is only tolerable as long as the mood-elevating effects persist, when this subsides, the association is no longer useful or motivating but becomes unsettling and unpleasant, and it seems like only dissociatives are capable of doing anything about this. Benzos are OK... and usually will have to do if I am not capable of just riding it out... but are not the same, and usually not quite enough.
Whew, that was an unexpectedly long epilogue. In summary anyway, I empathise a lot, good luck, and please do report back.
