1. Stop beating yourself up. Your "slips" can't be changed. It's in the past. Look forward to what you're going to do starting today.
2. I think instead of giving yourself pep talks every night, maybe you should plan and prepare for the changes eating-wise you're going to make. Make a meal plan, prep for what you're going to eat the next day, cut veggies, portion out food, etc. Instead of simply self-talk, take action.