Fiancé leaving me

So my fiancé and I have been together almost 4 years but have been friends so much longer than that. We have a 2 year old daughter and I’m 8 weeks pregnant again. Today he told me that basically it’s not working out because “ I’m not the girl he fell in love with” that I’ve changed. We live in the same house so now it’s just him walking around acting as if I don’t exist. I’m just over this.