Having Trust issues with my girlfriend

What's up guys, I'm 16 (you're probably thinking holy s I'm inexperienced,well you're right) so I'm having problems with my girlfriend which is a year younger than me,and the thing is that I just can't trust her,so I'm getting all worked up about it and I kinda have difficulties. So I understand the main problem is myself,different from other threads I haven't spotted her cheating on me even tho we have each others passwords for Facebook ,but it's kinda uncomfortable because she deletes some chats,well i understand that but let's get to the point in what kind of relationship we have and what facts make me feel this way. So first off, it's a long distance relationship, it's been actually a miracle we pulled that off for almost 6 months , I kind of see she loves me because we meet each other at like difficult places, I met her parents and she invited me to a trip with them which was almost the most amazing time of my life. So some facts why i don't trust her is that she's really attractive while I'm not,and it makes me worried since she attracts other guys attention, and i can make her complex while she's with me because of my looks (oh btw those who want to comment true love doesn't need the outside of you just stop, she's 15 and I think we've heard enough of it already)that brings us to a problem that's fixing itself is her becoming more mature, but the main problems are,well believe it or not,gonna sound weird but she's horny (I've slept with a few times and i was the one doing nothing and she just like use me as a toy) and she's reuniting with her exes and the guys she likes before me, I mean its okay to have different gender friends but she's the one that started it all ,and she's making friends in class,which are boys too but that doesn't really bother me,lemme tell you a story that happened recently , a totally random guy called her and literally talked total shit, the voice looked a bit like her ex's but not quite right,she decided to ask him if he changed his number ,that wasn't the case but she started talking to him normally and they met the next day ,my trust issues have totally blown and she asked out the guy she liked like a month ago saying they should meet ,this type of stuff kills me,maybe she can't takr LDR anymore. I really like her but what does it mean,she said I changed her life and made her more mature because she had a thing called "boyfriend carousels" and I was the one who put an end to it as she said,but is it true,can i continue my relationship? What do i have to change? Or should i end it because it means I'm not ready for it. TL;DR a teenager having trust issues with his more teenager girlfriend

Sounds like a no win situation. If you want to keep her all to yourself, you will be fighting a losing battle. My suggestion is either be ok with it, or let go.