Fuck. This is rough.
First off, there's nothing you can really do right now except laugh your way through Hell, because this is pretty much as bad as it gets. Seeing someone you love betray you in the worst way with your own eyes can seriously ruin a person.
We have been together for 1 year now. Its my first ever girlfriend, and im really proud. Im not a good looking guy, and I know she could do so much better. But what I do know, is that im a nice guy with a heart of gold. A heart that last night got shredded into pieces.
The fact you're a nice guy means she will feel guilty about her actions, but it wasn't enough to stop her from doing them. If you're willing to admit she can do so much better then this means she is almost certainly aware of this and has decided to act upon it. She probably does care about you, but she's only 19 and I can almost guarantee she didn't fully consider how it would impact you. Why? Because she's young and wants to explore herself and her sexuality. I honestly think 18-21 is the most difficult time in someone's life because this is when many of us lose our first loves.
Now, the day after, im laying in bed. I think I've cried out every single tear. She has tried to call me 13 times. Sorry I don't feel like writing anymore, I feel so... What im asking for, is what im supposed to do. I should leave her I know, but she means so much to me. Help. Again sorry if it was hard to read im just trying to write while i actually wanna go kill my self.
Don't kill yourself. When you hit rock bottom the only way to go is up. Right now you need to focus on eating regularly and distracting yourself, preferably with something or someone new.
Trust me when I say your relationship with this girl is over, and she knows it. If you try to salvage the relationship you'll look like a fool and a doormat. Even if she stayed you would only resent her and this would be toxic and only drawing out the inevitable. You need to forget this girl. Lose her number. Change your routine and take precautions to avoid her if necessary, but make sure she is out of your life.
Next, do a few things to boost your confidence. Perhaps a haircut? New shoes? Definitely some sort of new physical activity. Make sure to get outside a lot. Connect with nature. Look at squirrels and shit. I can't stress the physical activity part enough.
Find some new music. You're entering a new chapter in your life and it will need a soundtrack. This might sound stupid, but it's not. New music will help you heal.
She won't stop texting/calling me. I haven't answered any of them. Also her friends keep sending me facebook messages telling me what a bad boyfriend i am cause im ignoring her! Wow... It doesn't bother me at all though. Even though my heart is broken at the moment, I feel a strange relief. I can finally move on from that bullshit.
Kudos mate! Ignore her! Do not contact her. Ignore her friends. If they're actually trying to accuse you of anything right now then they are total thunder cunts whose opinions don't matter. Forget them.