Serious Help NEEDED!!

My son and I were recently reunited (he is 27). He knew he was the product of a rape (happened when I was 12), so what happened between us, really confuses and bothers me. When he came to Nevada to visit me, he got high (I was drinking wine coolers) and proceeded to kiss me--after asking if he could see the "scars" he left on me (stretch marks). One thing led to another and we ended up having sex...it has happened 3x since our initial meeting (he also tells me he loves me--I thought it was a bmom-son-thing, but to him its not). I've told him that we CANNOT be doing this, but he insists that he can't help himself--i'm irresistable to him Needless to say, when he went back home, I told him I was dating (it had been 3 yrs since my husband passed away and he knew I had not had sex with anyone during that time--I feel like the preyed on that!). He appears to be VERY jealous of the new person in my life...of anyone for that matter. Now, he won't call me...he only texts me, but its not the same. What can I do? I don't want to keep having sex with him just so he won't abandon me! Please help me!!