How do you walk away from someone your in love with?

She deserves so much more and right now focusing on school and myself is important and I can’t get distracted because when her and I fight it’s pretty bad and I cant focus on other things besides the fight and etc. I can’t give her certain things especially things I know she wants and it’s not fair to her. Its so hard to walk away from her when I love and care about her so much. Am I making a mistake? Idk what to do