I feel like I'm going crazy...

I don't know what to do anymore... I feel like I keep pushing my fiance farther and farther away from me. I don't want to get hurt... I'm constantly starting unintentional fights about petty bullshit. I'm extremely insecure about myself... everything about myself... I love him with every single partical of my being... I just don't know why I can't just let things be. I pick and go on and on and on about stuff until he blows up and gets mad at me when I deserve it and I cry and say I'm sorry... but I think I'm going to end up pushing him so far he breaks up with me... even though he says he never will that he will always love me...