I want my ex back so bad 😪

Hey guys, so me and my ex boyfriend broke up around the end of September...he tried getting me back days after we broke up (I broke up with him) I didn’t wanna continue my because I wanted a break and everything we tried to do in a relationship wasn’t working... anyhow.. shortly after I talked to a guy for a couple of weeks it didn’t work out because I’m still in love with my ex.. I called my ex yesterday crying asking could we fix it and he said his heart wasn’t in it and that I’d get over it.. he told me he had a girlfriend and that they started talking 1 month after we broke up. He said he doesn’t love her but it’s getting there.. I don’t understand how he could move on so quickly I feel like he didn’t love me if he could not wanna start over with us being that we were together 3 years vs the girl being he’s with knowing her for 1 month. I’m so depressed and sick I just want my baby back.