If you find yourself in this situation, do not waste your energy with feeling foolish that you didn't listen to yourself that things weren't right. You are seldom alone in that. Don't panic and start making promises you probably can't keep as it will only make things worse. Find someone with a cooler head than yours - who is trustworthy - to talk with. Don't try to weather your crisis all alone.
Finally, try to realize that what seems like your own private hell right now may in time become the turning point where your life changed irrevocably for the better. Live by your inner principles and you will have nothing to regret.
Regards,
Cheryl