Yes, don't go back. If you go back, they will keep your BB and kick you away.
I think the problem is with your c6, not just with your 99. If you c6 treats you well, I think your 99 won't be so bad to you. Yes, you are marrying to your c6 and not 99. But if your c6 does not respect you and love you, why need to keep this relationship?
A happy family means everybody is happy in it. If you are not happy, how can your BB be happy? Just keeping all unhappy people together won't make a happy family. As you have a job, bring up the child by yourself and I am sure he can grow up happily.