I have no idea what the problem is...I need help

[SpecializedX3]

I have three problems that i havent found answers to, they are in order of least to greatest.
1. every time I load a saved game the crewmen tell me that "we are taking damage", then "hull damaged" and then "all stop". it is really irritating
2. sometimes i will randomely blow up. i know this could be mines but it is not. for example, if i am at periscope depth, things are fine but if i go any deeper than that, i will blow up every time. it is a completely random thing that i have not found a pattern in. the only pattern is blowing up everytime.
3. i am currently in a mission to patrol of the Palau islands, i have done this for a really long time. i have returned to a port to refit about 4 times, sunk 42 merchant ships, 19 warships for a total tonage of 220469. and it still will not let me complete my objective. there is some glitch or problem that wont recognize my completion of the mission.
i have all current patches installed and am out of ideas. i would appreciate any help you all may have.
thanks