Sabotaging my own relationship: help

I’ve been with my boyfriend for 4 years now. We are getting married in December and we love each other very much. I can’t picture my life without him, he means the world to me. He is very sweet and caring and always tries to calm things down when we get into heated arguments. I admit that I start all of our fights. I hold grudges very easily. I get angry over meaningless things and I just don’t understand why. This obviously affects him but he always tries to make it work, even if I cause scenes and it’s all my fault. I get so jealous and I hate the idea of him getting closer to ANY girl, even my friends whom I trust. I don’t want to be like this, I don’t want to lose him, but at the same time I don’t know how to get over this constant burst of anger that I have. He came a long way to see me these past days (we are long distance for now) and I’ve ruined everything by fighting with him. Now that he’s gone I feel absolutely disgusted by my behavior and regret the good times we could’ve had. We talked it through before he left and we made up but I’m still very angry at myself.

I’m sorry for making this long but I’m just very sad.