Should I miss sex with my ex?

I'm 23 and lost my virginity to my ex-bf who is 30 and a lot more experienced. He was great in bed, and always bragged that everyone else he had been with felt the same way. He even made several women (including me) squirt for the first time. Even though he broke up with me 4 months ago and we don't even talk I'm still too afraid to sleep with/date anyone else because he always (before we broke up) said very few guys are amazing in bed and I would be really disappointed if I ever had a hook up. I don't want him back but I miss having sex and I'm so scared that he's right and being with someone else will just me depressed and gain weight.