Consider working with a therapist or on your own to raise your self esteem. It may be irrational and a product of the previous experiences you've been through, but you don't have to hate yourself for feeling how you feel. Do you have your own friends? Consider making friends of your own. And again, I think you might benefit from feeling better about yourself in general.

Self disclosure: I am insecure too (and while I'm not in a relationship atm, I'm insecure in dating. At least, last I checked. I haven't dated in like a year). But I think its ok to ask for reassurance from one's partner from time to time. So if you need to do that, maybe he will be receptive? Don't hate yourself.