100NL: Pretty lost here

[TheDespot]

100NL 6max online

Hero ($87.25) is button with 10d-10s

Folds around to CO ($104)who raises to $3, Hero calls, SB ($102.25) calls, BB folds

Flop 7h-9c-6h (Pot: $10)
SB checks, CO bets $5, Hero raises to $15, SB folds, CO thinks for a bit and calls

Turn 7h-9c-6h-Ks (Pot: $40)
CO bets $20, Hero??

This villain I had never played with before but he was moderately aggressive. I didn't have much of a read besides that. I had ~$70 left here and I was pretty lost here as to what to do. Thoughts?