This is a great goal
@sonicwhite to get off the street drugs and get legit help for the underlying symptoms. You can do this. If you are willing to get clean, then you absolutely can get the treatment you need for he ADHD.
There are a lot of studies that have been done that really push for proper treatment of ADHD and any other mental health conditions for people using other drugs as a part of getting sober. It's a huge push in addiction medicine right now. It used to be seen that someone had to be clean before the underlying conditions could be treated, but so many studies have been done that show that concurrent treatment of the underlying condition as well as the addiction is just as effective, if not more so.
That means the addiction has to be treated at the same time. That takes hard work and what will be life changing commitments from you to do that work, but this is all very possible.
They have done studies and found meds like Welbutrin and Vyvanse really effective for treating ADHD for people using street drugs, even while the person is still on the street drug, and it can help the person get off the drug they are abusing to treat the underlying ADHD co-currently with treating the addiction.
Your best route for success is likely to be to find an addiction medicine doctor or a doctor who treats people seeking to get off street drugs. They are the most likely doctors to treat the underlying ADHD, before, during, and after you get off the street drugs.
If you go to a doctor just looking for ADHD medication, without addressing fully the addiction and seeking to work with the doctor to get off them, you are likely to set yourself up for failure again one way or another and you will end up worse off than you are now. You will either have to lie to get the stimulants and that will eventually fall apart one way or another, or if you are honest, the doc may be very likely to see you as drug seeking if you seek out getting stimulant medications while also on street drugs, and docs don't like taking risks with patients they see (rightly or wrongly) as drug seeking.
In terms of taking stimulants, it actually doesn't matter too much if it was the weed or the speed that caused the psychosis. The fact that they are worried about psychosis on the stimulants at all shows they are worried you will abuse the stimulants. Stimulants very very rarely cause psychosis at prescribed levels when taken in prescribed fashions (i.e. as whole tablets and not crushed.) Stimulants can cause psychosis when someone abuses them. Amphetamine induced psychosis is so common, a number of research studies have been done on this phenomenon to understand it better. Even if the stimulants would not cause psychosis for you if you abused them, it doesn't matter. It's your behavior and choices to abuse drugs that they are worried about more than even the psychosis. The fact that you are at high risk for becoming addicted to them is the big problem. It's not just your well being on the line, but the doctor's license, so they are highly motivated not to give you stimulants.
Stimulants/amphetamines are medically contraindicated for anyone using street drugs. It can fuel the addiction like gasoline on a grass fire. The street value alone of most stimulants is quite high. The average psychiatrist is very concerned about giving stimulants to someone on street drugs, because they believe it could be sold for more potent drugs, or taken in inhaled forms instead of the form they prescribe it, which would totally change the effect and again, fuel the addiction to the street drugs. If they did agree to it, you will likely have to sign all kinds of contracts and make clear commitments to get clean, and they could be putting their license on the line, as there is a big push by the DEA to lock down on prescribing controlled substances in the US right now.
It's going to be a much easier road to get the ADHD treated by seeking out medical support to deal with the addiction and ADHD
together.
It's a good path to seek out this help as soon as possible. Not just think about it, but act. Call an addiction medicine clinic or rehab facility today. Not tomorrow, today. The more you use the street drugs to control the symptoms, the quicker they will stop "working," and they will stop working. They absolutely will stop. Then you will have all the old symptoms back, along with new problems, because you will feel like you need the street drugs just to function. You are also actively damaging your brain as you go, and this will make it much harder to treat any of the underlying symptoms. There are very few old drug addicts for a reason. Most people either get clean or die. But I think you already know using the street drugs isn't a good path.
If you are ready to do the hard work of getting off the street drugs, it will be relatively easy to get help for the ADHD. If you are not ready to deal with the addiction to the street drugs, then ADHD is the least of what you should be concerned about. Brain damage, organ failure, accidental overdose, lifelong depression, ect etc, and of course, death, should all be high on your list of concerns.
You can choose a different path. You will likely need help, and you are good at reaching out for it. If you are willing and ready, God will be there too to help give you the strength and help to continue on the path. You have got to do the work, and I think you can.
I hope you find a good doc asap to help provide support and good solid treatment so you can get better long term treatment, real treatment for the ADHD and PTSD as well.