Nuthatch makes an excellent point.
Additionally, I wanted to mention when I first saw this thread (but it must have slipped my mind
) that my mental health issues give me symptoms similar to what you describe: poor memory, problems paying attention, etc. I have depression, anxiety disorder, ADHD & PTSD.
To be honest, I think much of my anxiety is caused by untreated ADHD (my shrink "doesn't believe in prescribing stimulants
", nor does she really even think that ADHD exists at all...getting a new shrink soon (no, really this time)). Poor memory & such can be a symptom of depression/anxiety/ADHD, poor focus, same thing. Also, lots of people end up 'self-medicating' to point with illicit drugs
use is VERY common in people who aren't treating their ADHD appropriately (btw, appropriate treatment doesn't necessarily include stimulant medications, though it can).
Particularly where you seem to feel hopeless without drugs, this is definitely something you need to see a therapist AND a psychiatrist about. Depression especially is no joke & not something you should just try to brush off.
If you do have any mental health issues, once they are being treated appropriately (whatever that means for you - and *should* include more than JUST medication, btw), you may find your overwhelming desire to get high fades out of your mind.