Wow! That is quite a story for someone so young! Seems like you have a lot going on. Growing up as an ADHD child was probably something that was dificult. The childhood is vital to your progression into adulthood and I cant imagine that it made studies easy.

My biggest piece of advice is that you stop the drinking. YOu are young and it seems like you have done quite a bit of reckless things that eventually will come back if you keep on the path. A lot of this impulsive behavior is pretty consistent with Bipolar Disorder so if you honestly have concerns, you need to speak to a Psycologist. The longer bipolar goes untreated the harder it becomes. I was diagnosed Bipolar at 17 and trust me, seeking early treatment was really a good thing.

I am really sorry that you are struggling, but please, speak to someone. You can live normally without intrusive thinking. You just need a little help along the way. best of luck friend.