Welcome to the Bay of Death. From 43 onwards what you experienced was typical of the Uboat commanders life. They had to hug the coast down to spain, run along the northern Spanish coast to keep as far away from the aircraft as possible.
You are lucky you have working radar detection gear. A lot of the skippers and crews lost their lives because they had almost no warning of A/C attacks both daylight and at night. (Read
http://en.wikipedia.org/wiki/Leigh_Light on how the night became nightmare for uboats once the Leigh lights were fitted to Allied A/C).
Gotta love the realism this sim brings.