How should I play against three-bets with pocketpairs?

[_Overseer]

Since I preflop-raise quite a few hands (15 PFR) I get reraised a lot by aggressive players. I open to around four BB and they raise to about 12-14 BB. Now, I feel comfortable with calling (or sometimes make a four-bet) with JJ+ but lower pairs make me think about whether or not I really get the odds I need to call even.

The players that three-bet me are aggressive and often continuation bet 80% of the times, or even more often. When I flop a set the play is pretty easy, but what do I do all the times when I don't flop a set? Should I bet out or check-raise them with nothing sometimes?

I'm lost here, so any thoughts would be appreciated!

(My last post about this got locked but I didn't get any reason why, so I try to post it again.)