How do i stop my girlfriend from wanting to breakup our long distance relationship?

Don't. If your girlfriend wants to break up, respect her desires. She is setting a boundary for herself and if you care about her you will respect that. You cannot make someone stay with you if they do not want to.

Talk to her about it. Ask her why she wants to end it and see if there’s a way to save it. There’s always a reason for everything so try to get to that reason. If you and her love each other than you guys can work through it together and get past it. Doing nothing isn’t gonna help. Think if it’s something that you’ve done or haven’t done to cause the situation. For all you know it’s a very solvable solution that you just have to find. In the end you’ll be ok there’s a lot more fish in the sea.

Unfortunately you can't. Long distance relationships can be very hard, and they are very hard, to maintain. It may be hurting her more than it has helped her in the past and if she is not happy, you should not try to convince her to stay. Give ehr space and time, and if she wants to try again, she will. If not, move on :) Let her ba happy and you will be too.

I honestly think the harder you try to keep her the messier it will get. I think you should just let her leave, if she has made up her mind. There's no point in asking someone to stay when their heart just isn't there anymore