Need some help with insecurities/jealousy.

So, I have just entered into a serious relationship with the girl of my dreams..

But the problem is that I keep feeling the green-eyed monster creep into my thoughts. It is causing me to behave in a manner I normally wouldn't. It's making me feel even more insecure than I normally am, and it forces me to act out in plain immaturity. I don't like to admit that I am a jealous person, I used to be in control of it and I was able to curb my jealousy in the beginning of our relationship. But, as much as I try to fight against it, sometimes I just can’t help but feel it.

The real issue that worries me is that my jealousy is making me act out against my girl even if she is innocent and has no idea why I get upset, and also, it fosters my own low self-esteem. I just want to learn how to control it, I feel so helpless when it happens, these emotions work me to regrettable levels, I do and say alot of things that I later feel ashamed and embarassed about.

I feel a myriad of different emotions when I think about her past and her being with other guys. She has made some choices that I don't agree with, but she went through a hard time and these are things she can't change or do anything about now. So I don't judge her for anything.

We have been communicative about my issues, and she has been very understanding and accommodating.

I just want to find a way to get over it, so that it won't get in the way of our relationship.

Any suggestions?