Your poor thing. You have probably indeed had a stroke, which is a bleed in the brain, and this has caused your symptoms. I cannot get over how you did not go to the emergency room right away. But you should go ahead on over there today, if you can. The alternative is to call and make an appointment with a doctor, but you might have to wait a few weeks to get in to see him. As for whether it's reversible, I suppose they could still operate and get the clot out, that is sure to be in your brain, and if nothing else, they can get you involved in stroke victim rehab so as to help you regain some of your lost mental skills.
On the other hand, it is possible that you have actually just had something happen to your right eye, like if pressure gets too high in the eyeball, this happens to all sorts of people and is called glaucoma, it can damage your eye. The visual distubances that follow can sometimes disorient a person so badly, that they cannot think straight.
Then there's another possibility, and that's you may have a growth near the optic nerve, which runs from the eye to the brain, and it's pinching on that part, and that can goof up your vision, PLUS the growth itself can push on other parts of the brain, giving you your problems with thinking clearly. Once again, they would want to likely get that out of there, the sooner the better, and perhaps you'll need some rehab afterwards.
The tests the docs will do include a scan of your brain, to see what's going on in there, so they can identify what caused your problems to begin with. I do not believe that you are experiencing psychosis from the drugs you have mentioned, I'm familiar with them all. But what CAN happen is, for example, and this is only with the MDMA, if you use it several times a week for many months as a lifestyle, it can damage your brain, in which case the doctor will be able to tell just by looking at the brain scan, so rehab will be what they'll do for you, rather than any surgery.
So, get thee to a doctor just as quickly as you can, even tho time has passed since the original incident, as I've pointed out you could have a growth in there that needs to come out, or could be the clot from a bleed is pushing on the good parts of your brain and needs to come out, and in any case, you need to be in rehab for a while to get your thinking skills up to par. And as for drug use, as long as you don't take any with you into the doc office (smile), you cannot be prosecuted for having done them in the PAST.