I need advise!! Please!

So my boyfriend and I have been together for three years going on four, and we have a beautiful girl together... But recently I've been thinking about our relationship! Since we had our kid I feel as if he never wants to be around me, we don't cuddle we don't do anything as a couple... At all!!! like we even haven't had sex in like 2 months.. And it's getting to the point where I just NEED affection, and I know for a fact that he won't change ( he's told me)  We've been "trying" for years and nothing has changed! And I'm wonder what I should do?!