Very very loose table with a fish playing about 75% of his hands in the dark until showdown.

Preflop: I open 9Thh from UTG 30$ (stack 3k) , called by UTG2 (fish who plays dark, stack 2k), UTG 3 and MP and HJ (all loose players (stack 1.5k each). A weak reg 3b 150$ btn (stack 1.5k). I call, fish who plays dark calls, and MP calls.

4 way. (pot: 615)
Flop: Td5s7h. I check, fish donk 200$ after looking at his cards, MP folds, reg flat calls, I call.

3 way. (pot: 1215)
Turn: Jd. I check, fish checks, reg bets 350$. At this point I see the fish give off a noticeable sign of irritation and is rechecking his cards before holding them ready to muck. I move all in for 1350$, the reg's remaining stack.

Some background on this reg, it's a guy who normally plays the 1/2 and sometimes 2/4. My guess is he's shot taking at the 5/10 that night because the table was truly very good. He had been playing very tight and very straightforward at this table, especially considering as there are 6 extremely loose passive players who call down 3 streets with bottom pair and who never fold to a raise. Given all this the worst hands he can be 3betting here is probably AQ or TT-JJ.

In hindsight I don't like my call preflop at all as it puts me multiway in a inflated pot OOP, but my reasoning at the time was that I'm getting incredible odds and the multiway nature of this situation (playing against 3 passives who only bet with a strong made hand) will let me realize my equity more easily as the reg's bluffs will be greatly reduced. I don't know if I like my call on the turn either given that the reg has very few unpaired floats here when he flats the fish's donk, but with 9T there are so many good turns for me that my plan was to check shove any turn I picked up equity on if the reg continued to bet, as the board gets drawier. As played preflop, please evaluate my postflop line?

Thank you so much everyone!