This is a tough spot. Especially due to the hand sample of the opponent and the preflop action.

Your opponent cold called your 3bet OoP and could be thinking that the CO was about to be all in and he was getting a better price for the call. Because of this I'm not certain I could fold here, though I'd consider it. That said I'd most likely call and see a turn and go from there. If the money went in (cause we got there) I'd take a note on the result for next time...

It seems like one of those 50/50 spots. Either your dominating or you're dominated... But I wouldn't put something as weak as Ax of spades out of the BB range-given the action...

I think you have a choice of lines here.

T8s is normally a call for me from the BTN vs a CO open, but 3 betting still works.

On the flop you can check/call with second pair or bet/call taking advantage of building a pot in case you make your draw. As played you can definitely call this raise size being in position. We also expect villain to be bluffing some %. The main worry for me is that he cold called a 3 bet which screams JJ,TT a fair amount.

I don't think this is a tough spot and is an easy get in and I actually expect to see AA a good bunch here and even vs JJ we are far from dead (back door straight draw there also).

Don't ever fold. If you choose to just call that's fine but I'd just get it in.

You have so much equity that you're only really heavily behind JJ/TT. You're flipping with overpairs and even basically flipping against higher flush draws since you have the pair+draw and will win anytime something like AsQs goes unimproved. Anytime villain shows up here with an odd KQ or AQ/AK no flush draw you're way ahead.