Welcome to the forum! Congrats on getting a deer. Congrats on your family addition too.
In modern society we are mostly removed from food acquisition and processing. The closest most of us get is handling ingredients in neat, clean little packages from the grocery store.
A small percentage of persons in our society specialize in gathering food from the wild via foraging and fishing, as well as cultivation of fungi, aquaculture, industrial farming, and ranching.
As a young person I became interested in learning more about the sources of what I eat. I was not content to continue consuming everything prepared from neat little packages from the store without having to smell, feel, touch, and see the process of how the food got into those packages. Meat was at the top of my list to learn more about.
I toured a hog confinement, and an industrial cattle feedlot. I also talked with all kinds of farmers including oyster aquaculture, organic produce, dairy farmers, row crop farmers, etc.
Some of my personal conclusions were that I supported GMO farming, I dislike food labeled “organic”, and “free range” is a nearly meaningless marketing term. I also concluded that I wanted my own large vegetable garden and I would greatly prefer to harvest my own red meat, birds, fish and other wild animals in lieu of buying meat from someone else. My freezer currently has morels, squirrel, rabbit, pheasant, elk, pronghorn, and deer.
The first time killing a large mammal can come as a shock, especially if that is not something you grew up doing. My 3 and 5-year-old kids handle animal carcasses and we eat the meat the same day or the next day, so it’s just normal to them. They were a bit squeamish at first but they are not so much any more.
When you’ve lived your whole life disconnected from meat acquisition and processing, and one day as a 20-something or 30-something you kill a deer and walk up on it I can imagine it could be overwhelming in many ways. That is normal and natural. The deer’s eyes fade from glossy black to a murky green-white, the intestines stink, and there is a lot of non-meat tissue visible. Also, you just ended the life of a being not too dissimilar from yourself.
In the course of human history it’s abnormal for a person to be so disconnected from food acquisition and processing for so much of their lives. In 99% of human history 3-year-olds got a front row seat to the process and precious few were probably bothered by bone-in meat. Those who were may have risked starvation.
Some ideas: practice a vegan or vegetarian diet for a while. No harm, no foul.
If someday you want to push yourself to embrace your primal ancestry to hunt, kill, and eat, give it another go. Expect discomfort and plan to push through it. Maybe back off deer hunting and try something a little less intense such as catching and eating fish.