My heart has always seemed insatiable and ever-changing, how do you overcome this?

I find it very hard to settle down with a girl, I have always loved a lot of girls, but can never settle down with one, no matter how much I want to. Not to brag, or sound like a douche, but I have about 3 or 4 girls I could easily date right now if I wanted to, and 2 of them I actually love (long history with both of them, dated them both before), but it seems I'm never satisfied, I'm always looking for 'more'. I don't mean this is simply sex, or good looks, or anything of that sort. I honestly don't know how to describe it, other than my heart is insatiable and always changing

Does anybody else have this problem? What can I do to help remedy it?