You think to much and sych yourself out. Let your shooting instinct take over and be confident. Don't think, as long as its safe, andjust shoot the deer. If you don't shoot you'll never kill that first deer and get that monkey off your back. I was the same way my first couple years bow hunting with bucks, does I was fine, I thought the shot choice needed to be perfect and everything had to be the way I felt comfortable with and it cost me some good chances at some nice bucks. I got confident and forgot about thinking and went out there ready to shoot and it happened before I knew it. The monkey was gone....25 yards head on? I know you havent killed a deer before but 25 yards, you need to not think and shoot,you could shoot that deer no problem even with an open sight shotgun. We use shotguns with bird barrels on our drives for point swing and shoot situations and we could knock down any deer at 50 yards. Shot deer runnin in the head/neck at 20 yards and not by accident.... Good luck and I hope you get that monkey off your back soon enough. WCL