Would have folded this pre flop with 5 people folding to the raise before you.Playing the small suited connectors heads up really isn't the best spot.

That's only my opinion and mixing it up is certainly fine any time.

Now that your in the hand...opp raised pre flop, c bet the flop turn and river. I may put them on AK, 8-8 and up. I'm not a fan of the call on the flop. With no reads it's hard to put opp on A-x. You still only have 4-5 here with a gut shot. Not the right odds...

But if you are convinced opp is c-betting with AK and not an over pair I may raise his c-bet instead of call. Try to push him off and represent a pair (you did call opps original 4x pre flop bet)

After you hit the 4 on the turn, and still sticking to your conviction that opp doesn't have an over pair, I might raise. If opp pushes back I fold.

RIver seems like no help. At this point opps bet of $1.80 into a $8+ pot seems like just enough to get you to make a crying call. Maybe make the call for information. At a .5/.10 table though that's a lot of rounds.