I'm noticing the black king doesn't have too many squares. If white can bring another piece into the attack that'll decide the game. There's the crazy idea of sacing the knight and moving white king up but is that too slow?

Black could try to untangle himself with moves like bxa, Qxb6 and also e5, Re6 so white needs to address that first IMO.

I think best way to stop black's potential counterplay is to fix the pawn structures. Perhaps something like this:

a7, Qa8 or Qc8
e5, c4; black is kind of in a zugzwang
Ng4, hxg
Kxg4, ... 

White's going to play Kg5, Kh6 next and I don't think there's much black can do to stop that.