Depressed & Suicidal Ideation

Hello friends,This past month has been very stressful for me. I'm just going to list some things on my mind. Sorry for this wall of text.• I'm a college student in undergrad; and I'm studying to become a registered nurse. I need a certain GPA to qualify for my program; however, I think that this semester is going to destroy my GPA. I'm studying my ass off in order to prevent this but things look bleak.• If I fail this semester, I will have wasted 2 years of time and money in community college. I will have to start from scratch in a vocational program. I don't know where to even restart.• I'm going to have to put down my dog/best-friend in a few months. I've had her since I was a youth. I'm not exactly sure how to prepare for her death. I'm not even sure if I want to euthanize her; instead let nature take its course. She's due to be euthanized in September but she's still so lively.• I finally met someone! He made me really happy, and was very patient with my inexperience. I felt good about being gay for once. (internalized homophobia)• He was talking to someone else the entire time we had been sexually involved. He said he didn't do anything with him; but he's in Vegas with him right now. I'd leave him, but the pickings are very slim; and I like him a lot.• When I see straight couples who love each other, I wonder if being gay is not right. Most gay people I meet just want to f*** or be FWB. Am I stupid for wanting something more conventional or "heteronormative"? Getting married sounds unrealistic in this lifestyle. I'm thinking of going back to suppressing my sexuality; it's brought me nothing but trouble.• My mom lies to me.• My Dad and I are close, but if he knew I was gay he'd disown me.• I have one friend. I've known him since childhood. This is the only person I trust. I love him & he loves me. (Platonically)• I've done things in the past I'm really not proud of. It affects me today. I would do anything to go back and change everything.• I have a crippling social anxiety that inhibits me from socializing; due to excessive sweating & panic.• In summary, I am really disappointed where I am now, at age 21.My academic and future career plans are crumbling before me. I am jealous of the relationships my straight counterparts are able to foster. I wish I wasn't gay. I wish my parents actually loved me. I just wish my efforts would go rewarded. I know life isn't fair. I try to be a good person; I admit when I'm not. I'm just so tired of people, life, etc.Post-Script: I am not a danger to myself or others. I just felt I needed to write this out. No response is necessary, but is appreciated. Maybe tell me what I'm doing wrong? How can I make life more enjoyable? I've already tried solitude.