Can’t Progress past the mission So!

For some reason my whole normal mode play through was wiped, so I can’t progress through normal mode again because it’s stuck on mayhem 3 which is stupid hard, so I tried to do it online but it will put me in a normal game not on mayhem 3 so when I leave that game having gotten to chapter 4 I went back in my play-through which puts me back to the start.

Please help gearbox tech support you are my only hope.