i'm beat, but why won't they bet or raise???

[ninja please]

.5/1 game on party/empire.

this was at the end of my first session in a long time to see the complete disappearance of my stack. embarrassingly, also the first session where i came across a 2+2er i recognized (and who recognized me), though he wasn't playing, just witnessing my downfall...

i'm dealt Jd Jh on the button.
UTG limps. MP raises, LP calls 2 cold, i 3-bet. SB folds, BB calls. all others call.

flop: Ad Kd 4c

ugh, could there be a worse flop for JJ? however, it's checked to me which gives me a glimmer of hope. i bet, all 4 call. i'm pretty sure that at least one of them has me beat. i'm assuming there's an Ax out there too scared to raise.

turn: 8h
i really would have liked to see a J, Q, T or a least a diamond here. but it's checked to me again so i bet. definitely unsure about this bet. however, only the BB calls. at least the PF raiser is out, but i'm still fairly sure i'm behind.

river: 2s
checked to me. i figure my only hope of winning is to drive out a K or Ax little with a final bet, though in hindsight if they'd come all this way with such a weak hand, they're probably not going to fold here.

caller shows down Kh Td. they must have made a really good read on me for QQ or JJ, because there're not really other hands that you'll see 3 bet pre-flop that they could be beating. oh well, that's party low limits for you.

anyhow, should i have thrown this away when i saw the flop, even with the check-calling? do i check through? when can i get away from a hand like this when the people who have me beat refuse to bet or raise?