I'm 18 and on a summer break. I'm supposed to send my papers to a university in one month, and before that I need to grind my grades like never before to ensure I get a good chance of getting there. 

This is getting fucked up by my relationship, or rather by my compulsive seek-out for potential problems and issues. My girlfriend went to a summer camp for two weeks, and I literally went insane:

 After one hour I started to think what a piece of shit she is (for no reason), then proceeded to think how fucked up the two weeks are gonna be, then sunk into a depressive state where I would wake up at noon with no strength to make myself breakfast, I would get into compulsive sexual self-gratification, and spend DAYS analysing whether my girlfriend is busy with steering a goddamn boat for 10 hours a day, or whether she just doesn't love me anymore. I spent like one week adversely devaluing my girlfriend for no reason and wondering why is it I changed my mind about her, and all of a sudden I got enlightened that I probably have abandonment anxiety and do it to feel better. Self-diagnosing myself was a brief relief but then I proceeded to one week wondering whether I'm enough for her or not. Funny thing is that one day I would be thinking crap about her and wondering how to break up with her, and the other day I would get drunk and send her 'ILY HONEYYY 😍🥰😍🥰❤💖' messages.

 I'm so sick and tired of this emotional roller coaster. Right now I basically have 24/7 anxiety over whether she feels the same about me or not. I can't do shit for my school, being barely able to do anything but watching netflix and jamming-out my emotions.