Yeah I kind of figured it would be like that, but right now I just want to be back to the way I was 5 years ago AKA No gut or love handles

, injury and depression are EEEVVIILL. So I have decided to cut for the rest of the summer up until Oct-Nov then start to rebuild.
I dont understand, why the lower reps? For example right now I'm curling 75lbs (free weight) 3x10 3 days a week. With 75lbs I breeze through the first 2 sets and I dont start to struggle until the last 3 or so on the final set, but its nothing major. So should I raise my weight to 80-85lbs and do something 3x6?
Man I just wish I could build and get rid of the gut, that would be ideal