Pot sized bets can mean a wide range of hands all the way down to top pair. You have 2 over cards, a strait draw, and a flush draw. You have 9 outs to the flush + 6 outs to an overpair + 6 outs to the strait (minus 2 from the flush). In total that is 21 outs actually making you the favorite. Even if he had two pair, it would still be a pretty even race (15 outs) race so I would shove over and try to hit something.