If they don't like folding you should get value from your strong-medium hands and avoid bluffing. He will fold on the river his flush draws and gut shots if not improved so you lose a lot of value on the turn.
There is a good rule of tumb *2x4 poker rule* , I play at 25nl and use it daily
So in this spot your opponet has 9 outs if he has flush draw (8 because Tc) giving him 16% equtiy, 8% if he has gut shot, 4% if he has pocket pair and 0% if he has 5x...
and if you raise 3x (18bb) SB need for his hand to have atleast 27% equtiy to continue and CO needs 36% equtiy.
Check out concepts like Pot odds and Implied odds.