Am I being retarded for fasting on lift days and eating on rest days?
I would just switch it around if you really want to keep fasting. Eating is important for energy and when you eat it is also important for the physiological state of the body at that time. So a simple example in a calories in calories out overall situation at the end of the week, if you don't eat on training days and lets say you have the energy to work out 500 calories every workout. However, if you ate on training days you'd have the energy to work just even 50 calories more then you'd end up with a better deficit at the end of the week (and your training would be more comfy).
Just to visualize it, lets take a split of 4 training days a week and 3 rest days. (also make sure to keep in mind that you do burn calories on off days, I'm just tracking calories lost from training)
Without eating:
M - 500, T - 0, W - 500, TH - 500, F - 0, S - 500, S - 0. Total calories lost from training that week: 2000.
With eating:
M - 550, T - 0, W - 550, TH - 550, F - 0, S - 550, S - 0. Total calories lost from training that week: 2200.
I would also just consider ditching fasting and instead start to track calories on a week by week basis. For me, fasting has always ended up with me totally fucking up calorie deficits and gaining, while also making me grumpy and tired on fast days. The calorie tracking also preps you to keep track of macros, so if you decide you wanna start training more seriously you'll already have your foot in the door there.