How to get over these insecurities?

I was married for 6 years, but my ex, change a lot, he started cheating and he never stop,he was 23 and I was 16 when we got married, now hes 26 and im 20,we are separated, and obviously after giving him so many chances,a woman tent to get tire and after years and years of beging for the left overs of his love, if at a time were you weak and another guy support u, takes care of you and wants to make you happy, you give up eventually at the end, because that person makes you happy, I met a guy thats 22 and I was feeling him, I wanted to try to have a relationship, but he told me that he wasent ready for a relationship and for me not to stress it that if it happen then it happen, so I decide it ok, because honestly I couldnt have a relationship yet if I just got separated from my ex, but this guy that now im feeling, hes always around millians females friend and I cant stand it, on the other hand I dont want to put pressure on him to star something, hes 22 and I dont think that his ready to take a relationship serious, so I then met the guy who I first describe that hes always around, only problem is hes 41 or 42 and in a way better being with someone that age because they more mature and they know how to take care of a woman unlike younger dudes, I first was sure about my feelings but after months of living together I realize that my feelings are growing for the guy that is 22 and got females around him, so I email him and he says we will hook up when I go back to my hometown and im willing to try and see if he wants to have a serious relationship, and leave all that hanging around with womans but im scare to get my heart broken all over again, what if he dont stop those hanging over or cxheats on me,even dough im in another town my feelings for him are growing, what should I do? HIS22 AND IM 20