I am sitting at $180 and donk villian covers (55/20 over 35 hands).

I am not laggy, but probably seem laggy at the table as I've been raising a lot and just nearly doubled up when I 3-bet a flush draw all in and was called by a straight draw (lolz own3d).

Anyways on to the hand

1. I open to $4 with [Qd] from mp to $4, donk on the button calls.
2. Flop [4h][4s], pot $9. I lead $7 and donk raises me to $22.
3. Turn , pot $50. I check and donk bets $40.

I am guessing there's a lot of hands with a 4 in it that make up his range, but I have no idea if he thinks KJ is a monster or is trying to push me off the hand. What's my line here?

This is actually a tough spot, how aggro has this guy been? I would probably muck it here unless you think he'll really felt with KJ or KT.