its never too late
if u love him still its not shameful to say sorry even if the mistake is not urs

I do it all the time
The fact remains whether u feel the relationship is worth holding on to or not
Sister its not about male or female or whos right or wrong
Its about holding on to something worth holding on to

If he is the one who is adamant then i believe no one except u can change his mind
If its an another person in his life then no one can help u except God
Have faith! and be strong!