Newbie perspective.

I am getting worried that he has called PF and I would fold flop after a 1.3x pot raise, especially oop. I have read that overbets like this may suggest a player is nervously bluffing. However, I am too inexperienced to risk this. I don't think I will get value in calling.

In a similar situation (heads up, oop on marginal-good hand) I would bet more aggressively 5xBB PF or just fold.