He is a warrior. Whatever he does would be fine. He just happened to fight two very good p4p fighters and lost. He can still do well at 140 if he wants.
Go back to Manchester! Eat a big fry up! Have 10 pints of guiness! And laugh about the fact that you fooled the whole world into thinking you could beat Mayweather jr and Pacman! And not only that you made 20 million at that same time! Cos thats nothing to be ashamed of! All the best!
Judging by the way his fiance was shaking in the aftermath, I wouldn't be surprised if he calls it quits.