Yes it's normal, just don't beat yourself up about it, my wife had to go into care as I ended up in hospital for a long time, I've always told the kids if I go the same way as her (early onset mixed, aytyipical AZ) in her case to put me in a home too. I have children so we love them, not making carers.
I did it through choice when I said "in sickness and in health" when we married my choice, kids never got to say they wanted us as parents, bit young at the time.
What you're feeling is normal but don't let grief ruin your life, it's not what I'd want for our children, all I can say. K