Okay. Well, lets just call the girl S1
I met S1 at the start of the year. I really focused on her personality as it interested me. She recently got a Facebook account, and since I am a VERY shy person, I started talking to her a lot on Facebook more than in person. We would have convos for hours on end with each other. One day, I told her how I truly feel, she said "I've secretly loved you too :)"
That made me have a warm smile in my heart. Anyway, she was already in a relationship with this boy that she really wanted to break up with because he cheated on her. But she didn't have the guts to tell him that because she didn't want to break his heart. Anyway, he finally dumped her on the school holidays. I was so relieved to be able to ask her out and be with someone who would treat her correctly. Then she somehow got back into a relationship 2 days later with this guy I've never heard of before. He seemed to be one of S1's ex. He has been in a relationship with her 3 times and cheated on all of those times. He has hacked her profile, reading my messages I've been sending her.
Anyway, this boy lives about an hour drive from where we live. Yet, they still seemed to love each other. I asked S1 if she loved me, she said yes, but she was still going out with this other guy.
So one day, she let me read this "death" message she wrote whenever she was going to die. One of the lines broke my heart, saying this; "Even though *insert boys name here* has cheated of me 3 times. I always get different emotions, but I know inside I will love him no matter what"
That really got to me. She knows how I sort of feel about her yet she still let me read it. Wouldn't she of known this would have hurt me terribly?
So the relationship seems to be continuing and getting stronger as moons go by. Now, you can call me the jealous type, but this man has hurt her terribly 3 times, they see each other about once every 2 weeks, makes S1 cry a lot, yet continues to love him.
I feel very deeply about S1, I don't want to use her for sex like 3/4 of the males at my school do. She's gone through a lot of **** through her life, and this mans not her to help her out when she needs someone.
We hang out practically every day, I comfort her when she's sad, I've kept all her promises. We've had a lot of fun times together, yet, I feel our friendship is getting worse. I'm happy that she's happy. But she's going out with someone who I KNOW will hurt her again. I don't want that to happen to her, because she doesn't deserve it with all the **** she's gone through.
So, this question is. How can I sort this problem out? I'm not giving up on her, I know I love her. So all you haters who say "she loves someone else, just find someone else" gtfo. I have many deep feelings for her and nothing will break that bond.
Any tips/advice or anything?

I get you have intense feelings, but you need to recognize she is stuck on those that are not stuck on her, and cannot see that you would be a better choice.

The only way to solve this problem is to forget romance, and just be a friend, a REAL one, because that's what she needs a lot more than a boyfriend.

See, and understand this flaw in her, and do not try to fix her, because you can't. She has to see her problems and want to fix them herself.

I understand the feelings you have, and empathize with you, but you can only do something about the feelings YOU have, NOT the feelings that she has. Romance with you is not one of her feelings, so if you can't be a real friend, with no agenda to have more, you need to leave her alone. That's not easy by any means but sadly a necessary thing to consider.

You she is really in need of help , a helping hand . She needs more of a friend although . I know you will be feeling a bit awkward since you love her so much but I think now as she is already in trouble you should not force her to be in a relation with you . Be more of a friend to her make her get rid of her ex and this will be tough , here you have to play some mind games probably everything possible . Then you can express your feelings and she will also understand it in a better way . Since no hardships are there .

I'm sorry to say, but she already knows how you feel about her, so if she wanted to be with you, you would already be together by now.

What exactly are you expecting out of her now? Are you waiting for the other guys to take their turn with her first and then it will be your turn next?

I think you're better off finding someone else who isn't leading you on and giving you false hope.

I'm not sure what "gtfo" means but I'm guessing is not something nice. And what's the point of askingfor advise if you are restricting us to give you our full opinion on your situation.

This is very simple. She is taken, and therefore off limits to you, at least for now. It sounds like she loves you, but as a friend. Right now you need to respect her by respecting her relationship. No one in this forum will give you advise on how to conquer her from her boyfriend with some "bf destroyer" techniques that PUAs use. And it will never be recommended to take her away from a relationship because everyone is allowed to make the mistakes they want to make and have the option of learning from them. However, you can be her friend which is something she needs right now and hope for her relationship to end at some point. Hopefully then she might develop a romantic interest in you but nothing is guaranteed. Also, if she does be careful because you might just become the rebound. I would personally recommend to leave her alone and to find someone who is available for you and wants to be with you NOW.

Good luck,
Javi