In reply to Simos:
Marek has a good point; you could be getting hurt during the climbing itself through drop knees, heel hooks etc?
When you land, you should try to roll backward. Dropping down into a squatting position is bad for your knees, your back, and possibly your face if you one day smash it into a knee after a hard fall!
One other thing; if you have generally poor mechanics/movement, then you have less of a natural movement pattern to protect you when doing lots of landings. If you are someone who squats with your knees and thighs rather than with your hips and glutes, then you are probably hammering your knees in both bouldering and daily life. You might find that strengthening your bum and learning to use your glutes more would help, and may even help your cimbing. Obviously I haven't met you so this is just a possibility - may not be relevant.