Too hard on myself

Hello everyone,
I just started like amonth ago and this has been a hard journey for me. I was doing really good for like 2 weeks and then i had too much food for that day. It has been nothing but healthy food, but I ovedose on it. I taked with my trainer about it and he said to just keep going and dont look back. But I continue to be hard on myself and I eat more than I should. I consume too many calories its depressing. I used to go to the gym everyday and now I go like 4 times a week. The scale still hasnt moved down. I had lost 2 lbs and now I went back to where I started. I dont know what to do to get my mind to JUST STAY ON TRACk. Please help.