I would have probably dumped it on the first bet on the turn with the agression behind you. The raises behind suggest you could be drawing dead to someone with QJ. Not to mention that 2 of your outs (7d and Qd) are dirty. Getting 7.5 to 1 is more than enough to play, even with 6 outs, but do you really feel comfortable if the Q hits?

As far as math is concerned, it is about 6 to 1 back to you, but again, I only feel comfortable if the non diamond 7's come out. Discounting my outs to about 5-6, I fold this hand.