Nicki, the ED "the sage one" has said it all.
You need your work for several reasons, don't feel guilty for doing it. Tom will feel better with you around when you come home. He should find something to do that is rewarding for him. Something like volunteering at a nursing home, children's home, church, whatever suits him. Even if his energy level slumps he'll still benefit from the human interaction outside your home. You have done a beautiful job so far and I know you will continue to do a beautiful job.
As for the crying, if I had a dollar for every time I needed to cry I'd be very wealthy. I am certain it is normal (else I'm not normal, and I'll hate when that happens) and very thereputic. Don't worry about it at all.
