I don't think it is necessary to protect here, and i don't like the way the protection is done. If it is sente, it doesn't mean it is good.

My idea was to take another big point, for instance 77 below.

There is no immediate danger of being cut, I don't believe white can actually play like below.

Moves 77-86  

the push from behind, of the game, really greatly helps white, i think.