Why does a guy only think about sex and not her feelings?

I broke up with my ex because he asked me for sex so many time, but the bad thing is that we only dated for about 1 month. Honestly I am still a 19 year old virgin, I never have sex in my whole entire life, and I am not planning to have sex until I get married. Well, I told him straight out how I feel about him asking me to have sex with him. Well just a little while ago I broke up with him, he told me that I shouldn't call him, and that when he is happy he will call me instead. I told him that if he is just gone a act like that then might ask well don't call me at all. Then we broke up just like that, then it made me think about my really great ex boyfriend. I loved him so much but then he and this recent ex has something in common. They both want sex. Now I think that was I wrong for leavin my good ex. But then I think about it, if they love me they will respect me. RIght? Someone please help me.