Guilt and change

I feel guilty. I didn't mean to make it sound as though I was blaming my mum for my problems. I don't blame her, she was sick and had little or no control over her actions and moods. But yet, I am doing the same thing, in a way. I can't seem to control my own moods and have hurt my girlfriend because of that. Hence, I feel guilty. She has been through so much adversity and is now even considering moving back to Tasmania. I feel partly responsible for this urge. I struggle to change, so so much. Why is change so difficult? I fear putting her under so much stress, oh please, I just want to change for the better so we could be happier together. She deserves more than just this; I really want her to be happy in our relationship, but first, I have to change. So why is it so hard?