Hello and welcome
I think that what you've to do is just remember that there are plenty of trolls online, and its better to get into relationships only with people you've gotten to know in real life. What you should do is get yourself into other positive activities that will help you to forget what happened and distract yourself with positive helpful thoughts. Examples include charity activities, music and maybe group activities such as cheer-leading ,choir and chess. All those function as good activities that you can really get into in order to regain back your enthusiasm and happiness.
You should also remember that those people who betrayed you in the past don't matter. What matters is the people who stand by you, support you and won't betray you. The people in life who're jealous of you or want to hurt you are willing to use all sorts of ways and methods in order to make everything worse.. but when they don't matter, nothing they do can affect you. Just care about those who care about you, appreciate them and things will start to get better.
I know that for now, it's tough, but i am here for you too.
you can beat this. And i know it's tough when you doubt yourself, but there's no need to doubt you.. there's no need to doubt someone who is hardworking, sweet, nice and has a bright future. Have faith in yourself cause you're a lot better than you think you are.