If i have a bad day of eating.what could i do to make up the bad day i lost and get back to dieting?

I am Morbidly obese.i have been doing great.but went to a party and thought i was strong enough to fight temptation of bad food.my family never supports me in my journey.i am 445 down from 496 natural weight loss.i dont want to go backwards.i eat like a pig and am pissed off.my weight is my problem i know but everybody can use help.i know i cant let this happen again.im at the party now.i want to leave.someone give me advice for the right direction.