Fasting - how to survive the first three days?

Hi, I want to go on a 21-40 day fast. Unlike my other fast this is a conscious decision (without spiritual association). The reason I am doing this fast is to heal my mind, body and spirit. I am so tired of being overweight. I am 100kg and 5ft4/163cm.
I want to learn how to love myself etc etc. I’m almost at 14 hours and I am determined. I am not physically hungry just mentally. This is what I am trying to rid myself of. Slavery to food and emotional eating. This is war! Any tips and advice?