Whoa, when you say the NHS will not prescribe amphetamine, does that mean that you could get them under private health care cover, or is the NHS in charge of authorizing drugs as well, like the TGA do in Oz?
If I couldn't get pharmaceutical dexamphetamine off friends, I would be in much the same situation as you, using street amps. Interesting to hear about meth in your neck of the woods. From what I've heard it was pretty hard to come by over there, but I suspect most powdered amphetamines that can be smoked would be meth. Getting racemic or dextrorotary amphetamines into a smokeable form is a fair bit trickier from what I understand, something about sulfates being far more hygroscopic than hydrochloride and or unstable at room temp? Not sure but like you mentioned, all the people I have talked to from the UK speak of smoking the oddly named base

Believe me, if we could get smokeable amphet sulfate like you do in the UK, I would be self medicating already! Here, you'd almost definitely need to be or know a good organic chemist to get illicit amphetamines, such is this city's preference for meth
What you say about SSRIs in the '80s and '90s is bang on. My dad is around your age and suffered a catastrophic head injury in '87. I honestly have no idea what he was on after that to treat the subsequent depression he has lived with ever since, but I know that he's been on a slew of SSRIs and SNRIs since, and he raised his eyebrows when I mentioned tranylcypromine and phenelzine, so he has obviously been brainwashed into thinking that MAOIs are outdated and ineffective. If ever I'd met a candidate for tranylcypromine or tranylcypromine with dexamphetamine, it was my dad 20 years ago.
I thank my lucky stars I live in Australia. We have access to nearly all the options the UK and US do for treating ADHD and depression; the only two drugs I cannot get here that interest me are Desoxyn (methylamphetamine hydrochloride) and tianeptine. Bupropion is only permitted for smoking cessation which kinda sucks but most depressed people smoke, from my personal experience. However, our safety net and the federal Pharmaceutical Benefit Scheme means that with my concession card, I can afford to try stuff like Selegiline and Moclobemide which would both be more expensive in the UK, the latter of which isn't even available in the US.
I cannot fathom why the NHS would put an upper limit of presumably 80mg a day on tranylcypromine. It is a drug of very low abuse potential in my view, albeit more easy to abuse than other MAOIs, but what the boffins in regulatory institutions do not realize is that they indubitably force people like you and I to seek out illicit drugs because they so tightly restrict the legal options. It is not uncommon in literature to find people prescribed as much as 150 or even 200mg of tranylcypromine a day. I am sorry your efforts to legally treat your depression seem to be stonewalled by red tape.