i was driving around and doing some missions then i got an CE error and my safegame was completely gone and now i'm again at the beginning.

I had a similar problem, was LVL 9 and gambled with my wife. She had a CE error and flew out. I then and then came a loading screen as if I would start the game solo, everything away now had to start again and have no tasks just orders! ... Really a shame ... Google translate!