Help with the save games

[Thunder]

been reading the various threads about this and need help, a definitive answer if anyones got. was sitting up a river outside Narvik, misty as hell, took a guess and fired a spread unseen into the fog. Four impacts(unheard of for me as im still learning olc's mod).
I had hit the battleship(i forget which(Nelson/rodney)which sunk. I went on 2 knots and sheltered in her shadow from the destroyers, which had lost their marbles and were going beserk around me.

I figured the pyrotechnics would contine for a while so i saved game hopng to return later when i had more time.
Upon loading sh3 (and gwx2) i went to my saved games and there was nothing!!!!
Sooooooo many tonnes gone! Why.What can i do to avoid this.The only mods are those that came with GWX2 and olc's manual targeting.(i do the mast height conversion in my head).

Any advice 'cos i do feel the need to get out the sub from time to time...season of good cheer and all that...