I think it would be worse to kill a meat animal and not eat it than to eat it, unless you are a vegetarian of course. If not its just someone else's animal has been killed for you to eat.
The first "big" animals I had slaughtered to eat were pigs, and I had let myself get very attached to them. It was difficult, but once I got past the first few hurdles, and they were in polythene bags in the freezer - and tasted delicious - it was not so bad.
Maybe leave it for a while before eating "him" so it is not too recent in your mind. And as others say he will be pretty fatty so will need careful trimming and cooking.