I'm sorry to hear the meds are banned where you live. I understand the reluctance towards meds, I have some reservations too and personally didn't find a lot of value in taking them (anti-depressants, anti-psychotics). I'm not educated enough about ADHD so I'm sorry I can't help on that.
Regarding more traditional advice like you mentioned, I think going to the psychologist is a great first step and it may help a lot. Are you looking forward to exploring that route? I recommend asking the psychologist directly which sort of therapy they'll give you (CBT, DBT, EMDR, etc) so you can then research and assess what you think of that methodology.
@EternalShore gave some nice advice that is traditional and can be done in a self help way besides the psychologist.
Do you journal? I think dabbling into introspection can help discover a lot about yourself, what your problems are, and that is already a good spot to start fixing them if that's what you want. Writing what you're thinking is very effective, much more than just ruminating thoughts.
You said you've been non functional for 6 years so I won't recommend exercise, because I know that is hard as hell, no matter if it helps with endorphins levels (unless working out is your hobby or unless you find working out easier than other things).
The best way that I've found, through the years, to restart being functional, is to start with very small and simple goals. So if you're non functional and you're not taking care of yourself or your space (this has happened to me a lot, for years...) then I'd start by deciding that tomorrow I'll clean my desk. Just remove any rubbish and pass a wipe on it, nothing else. It's a small goal and I'll have the whole day to do it, but it's something that I can do and regain some control of my life. Then on the next day I can pick something else of a similar size to do.
The reason why I mention cleaning the space around you is because a cleaner space can help with a clearer mind, it's a small form of exercise and you can feel like you ticked something off, that you were productive, which can help mentally.
Another thing you can do is to transform some of your current past times into something more active. So if you watch gameplay videos, maybe you could decide that you'll play a game instead of watching a walkthrough of it. This helps to get out of the usual passiveness of watching endless videos and not having the energy to even play a game by yourself.
These are all the ideas that come to mind now. I have tried many other things through the years and, depending on your level of commitment, I can share those, just don't want to overwhelm you with possibilities as I know that can be so tiring and cause someone to lose motivation. Sometimes we just need something simple and small to start.
