You should have 4 bet much bigger, to $75 or even $90ish
The smaller 4 bet actually looks stronger than a bigger one. With your read that he would likely call a 4 bet after he 3 bets, why make it so much smaller. If he had a stubborn AK/QQ/JJ that wants to see a flop first, we have to make the extra money PREflop. Should an unfavorable flop come vs that large portion of his 4bet calling range, he will have gotten away for much cheaper than if you had raised bigger.

Then the flop comes and you make another small raise, this SCREAM strong. You are probably more likely to get called by shoving the flop, like you are trying to bluff/protect a queen or JJ/blow him off with you're flush draw.