Alright, first I'd suggest turning the brightness up on your monitor, and the gamma up in the Counterstrike video options settings.
Then, I'd suggest calming down. CS and UT are 2 quite different games and you cannot play the same way in both. In UT you need to jump around alot and (if using rocket launcher) aim for their feet. In CS you need to move around stealthily (is that a word?), and aim for the head/upper body region. As mentioned before, in CS you do not want to hold onto the trigger until all your ammo is gone, you want to fire in bursts (2-4 shots at a time, release trigger to allow crosshairs to re-align on target accurately, then do it again) - there should be a slight (less than 1/4 second I'd say) pause in between each burst, but it tends to help a lot. While it's not necesary to do this with the MP-5 (Btw, if you're a newbie, use this gun, it's much more accurate and cheaper), it's still a good idea so you don't have to reload so fast.
Good luck, and stop whining