I was on 800mg of seroquel for a decade, then gradually got off it over 5 years and haven't had it since 2016. I really would think twice before using it in the expectation that it will leave you better off - particularly if you use it regularly long term. Helping you sleep and eat is certainly a benefit. However, I now have constant insomnia that doesn't respond to anything but ambien, which unfortunately worsens my major depressive disorder. My body also now associates being sleepy with being ravenous, so even though I haven't taken seroquel in ages, I haven't lost the weight I gained while taking it. My blood sugar is permanently borderline pre-diabetes - even when I've been on a keto diet for months. While I was taking seroquel, I was constantly sleepy. I finally had a sleep study and found out I had sleep apnea - not the snoring kind, but central sleep apnea where my brain just wouldn't send the signal for me to breathe. I believe this was due to the seroquel since I no longer have to wear a cpap and nothing else has changed except not taking the seroquel. I was also diagnosed with some sort of limb movement disorder - I was constantly moving in my sleep. Even awake, I can't resist constantly twitching my fingers and toes. This has been a permanent consequence, though I now take gabapentin at night which helps. I usually just say I have restless leg syndrome, but it's not limited to my legs so is likely a mild form of tardive dyskinesia which is caused by antipsychotics. And I'm lucky - at least the twitching doesn't involve my face, which has happened to other people.
If you want to take something for sleeping and eating, I would just take the remeron and not the seroquel. I've also been on that but had to stop due to massive and unrelenting weight gain - weight gain I certainly didn't need having already gained 50lbs on the seroquel.
I can also say that for me personally, seroquel does not appear to have prevented downregulation of my dopamine receptors (in my case due to the same idiot doctor who prescribed the massive dose of seroquel also prescribing a massive dose of Adderall). Of course, I have no way of knowing if the downregulation would have been worse in the absence of the seroquel - but that's hard to imagine since I can barely function as it is. My cognitive faculties have declined tremendously and I attribute this primarily to the massive doses of seroquel and adderall. I'm still on the adderall, though at a lower dose, because I become practically comatose from depression when I stop. I actually began fearing I was developing early dementia (seroquel is associated with cognitive decline and an increased risk of dementia), but my psychiatrist has reassured me that my symptoms are more akin to pseudo-dementia.
I'm obviously not unbiased on this subject, but I want anybody reading to fully comprehend that seroquel is no joke. The evidence for its efficacy for the use described is, in my opinion, not nearly robust enough to justify taking it in the off-chance it helps. I'm not even just basing that on my personal experience as there is plenty of robust evidence for the frequency and severity of side effects. Taking it occasionally for the comedown is better than chronically, but even occasional use of anticholinergics is associated with significant cognitive decline. It also may actually lead to increased stimulant usage - the only reason I even started taking Adderall in the first place is to counterract the extreme sedation and brain fog of the seroquel. And now I'm stuck on the adderall. So caution should be taken that you don't end up in a continuous loop of using the seroquel to come down, then craving meth even more the next day as a result, then needing to take more to get the same effect because the seroquel is still in your system.
Anyway, I'll conclude this novel by mentioning TMS (transcranial magnetic stimulation). As I've said, I have treatment resistant major depressive disorder. The most prominent symptom for me is the monumental effort it takes to do every little thing because hardly anything gives me satisfaction or a sense of achievement, let alone enjoyment. Unless I take meth, that is. Anyway, it got so bad this past summer that I begged my psychiatrist for electroconvulsive therapy as meds weren't helping and I was at the end of my rope. She wanted me to try TMS first, so I did. TMS is theorized to work by stimulating areas of the brain that have decreased activity in depression. It did help some - I still don't feel much enjoyment, but it did improve my ability to feel a more normal sense of satisfaction when I complete a task. I wonder if this kind of brain stimulation might someday prove helpful for stimulant post-acute withdrawal syndrome and/or as a treatment to reduce cravings for stimulants. It would be an interesting subject of future research.