feeling bad for moving on

Okay I need some help. My ex and I dated for 3 and a half years. We broke up about a month ago and I was so so tore up about it at first. Now that I've had time to think about things I have absolutely no desire to date him again, and I've made that clear. I've recently met this guy who I really really like. We talk all the time and I'm so into him and happy. But I'm the back of my head I feel so bad for my ex. He acted like he was all okay when I was hurting, but now that I'm over it He's telling me how tore up he is and how not okay he is. He's been trying to talk to me and texting me and I can really tell that he's taking it hard. But now I have this new guy.. who I really want to be happy with. What on earth can I do. I feel like I need to let my ex know but then again it'll really really upset him and I really don't want to do that. Yet another part of me is telling me to just not tell him at all and let him figure it out when the time comes. I still care about him obviously but I hate feeling bad for him. Please please help me.