That is ok. If you want to say it in a more casual way you could also say "We haven't seen you in a while."

We don't see you that much these days. Or we don't see you a lot these days.

Yes that sentence is correct. Though the other variations suggested are right too. Your sentence gives a particular emotional feeling which is lost a bit in the other examples. The sentence you wrote has an ordering of words which is more common when you speak rather than when you write formally.