I love her, i should let go but i cant

Im 17, i met this girl when i was 13 and i knew from then she was the one, its been 4 years since we broke up and shes moved on but i can't, we weren't even in contact and my feelings grew stronger, we've recently started speaking again and shes in a bad place as her ex wasn't very kind, im trying to help her be happy and understand that she is beautiful, as much as i want this to progress as we've both agreed it could, it hurts so much, i love her a lot its kinda weird, but she still loves her ex and even though she don't say it i know shes struggling to get over him, I've been told i should leave it and stop talking to her but its easier said than done, im only 17 and this is killing me, what should i do 😢

First thing you should do is make her realize that her bf is a douchebag, and shes just wasting her time and effort into someone that doesnt really care about her.
The second thing you should do is make her feel better make her feel that she deserves someone like you.
Never give up on her if you really like her do everything that you can to comfort her and to make her realize what shes doing : ) just focus on helping her first and she will eventually like you for helping her and make sure you show that ur interested in her : )

This is a difficult one. She may not be consciously doing this but she is just taking advantage of you and your love for her. You are her emotional tampon. Being there for her will not likely pay off like you think. To her, you are just a trusted friend, not a potential lover. She is a hot mess of emotions, and by no means will not be in a right place for a relationship even when this thing with her ex is over. Coming to her rescue is call shining knight or white knight syndrome. You are going about helping her for the wrong reasons....you are doing this because you want future with her and to encourage her to stay away from her ex. This is bad bad bad. You are setting yourself up for a world of hurt, because she will either go back to her ex, or will reject you telling you she isn't ready for a relationship only to meet some other guy and start dating him. Trust me on this, people over exaggerate how bad their relationship is. You must keep in mind you are only hearing one side of the story. Never think she is an innocent, there are things you will never know what has happened between them.

IMO you are best to keep your distance, and let her learn to stand on her own two feet. She has family and GFs she can talk to. Nothing wrong with keeping in touch to say hi, or even take her out for a coffee to have light conversation, but do not discuss her relationship issues. Stay out of it. If you keep involved, all you are doing is making yourself a part of this mess, and eventually she will want to (if she does) distance herself from everything to move on and that would include you. Don't get involved anymore is best.