Late war attacks quite differ from the easy night surface runs against 1-2 usually inexperienced escorts. In 1942 destroyers and aircraft have radar so no surface attacks any more. You should have a radar-warning receiver (like
Metox that is available from mid-42) with which you can get ahead of the convoy outside escort radar range (at least about 10-12 km, however they can detect you sometimes from 20 km).
For the attack you should always submerge and if you have Falke acoustic torpedoes, attack the escorts with them. Right after you fire your torpedoes dive immediately, you can follow your eels through your hydrophone, too.
If you previously played SH4, I advise you to start a career in 1940 to get used to the capabilities of your U-boat and find out the enemy's tactics.
Finally, should you still fail escaping escort after not so fruitful attacks, don't worry since in real life many U-boats were sunk even before having a chance to shoot their first torpedo. If stakes are against you, keep in mind that there always be a next convoy somewhere else in the ocean.
