It's sad, but at the same time dogs and cats are animals and probably don't experience this the same way you do. It's good that you try to be different yourself, and it is probably too late to help your mother or father. It might be least stressfull for your mother if you let it rest.
I certainly wouldn't join the army, because in essence its still a place which trains you to commit one of the most violent acts of all. Many more normal people develop mental issues there, and with your background you certainly have an increased risk of that happening. Just try to last untill you get a normal job. I think you can be proud of what you have already accomplished so far, both in study as in developing yourself as a person.