Need advice.

I broke up with my ex fiance about six months ago and I'm together with my current boyfriend and have baby number 1 on the way. I've known my current one for about five years. And my ex fiance for only a yet and a half the time we dated. Recently , I haven't been able to stop thinking about my ex like he stays in the back of my mind. I want nothing to do with him tho because he cheated and lied and used me the entire time. I feel like this is messing up my current relationship. I don't feel as close to him as I use to. I feel like he's too clingy now always wanting to hold my hand kiss me be attached to me it's like I can never have my time and I've tried talking to him. Ignoring him a little bit here and there but he just won't stop. I don't know what to do....