Hey /sci/, ex-mathematician here.

I used to love math back in primary school - I used to excel at it, it was like second nature to me, I went to international competitions and all that jazz.

Depression struck me in electroengineering high school, so I lost all interest in mathematics, and since the schoolwork was fairly easy, it wasn't a problem for me.
I started flirting with the world of drugs and started drinking and smoking weed on a regular basis. My interest in science and mathematics degraded even more.
About a year ago I got a lot of bad shit happening in my life which made me even more depressed, I started railing speed and taking MDMA until I hit rock bottom and planned a suicide.

Now, I got myself a good therapist who really cares about my well-being, I'm gonna get my meds tomorrow to reestablish the balance in my brain. I'm stopping alcohol, weed, amphetamines and mdma forever. However, I will finish high school in 2 months and my mathematics skill has degraded a lot. I don't even remember the last thing I did in school, my mathematics skill is at the level of primary school.

So, how do I continue the path of Mathematics outside of the school? I would like to get back on it, but I don't see a way to return - it all just seems so chaotic and shattered all over the place, I just don't know where to start and where to go.
Are there any books online that are basically Everything about Mathematics? Or at least some guidelines?

Any help will be appreciated.