I have a number of possible ways to provide some relief to the situation.

Call your Health Region. There are likely programs that can assist your mom and provide some much needed relief.

Home Care. They may be entitled to bring in a nurse or home care worer for a couple of hours a week. They can assist your mom with the more difficult tasks involved in caregiving like bathing your father, etc. It may be possible for your mom to get away for a few hours.

Respite Care. Some hospitals, senior care homes, and extended care homes offer respite services. This means admitting your father for several days so as to provide your mother some respite - a break from the stress and opportunity to look after her own needs.

Support Groups and Classes. In addition to the above, my father was put in touch with a support group for caregivers. In addition, he was able to take some classes in how to care for someone with my mother's needs. He also attended a Mood Disorder support group to help deal with his Depression.

Finally, I think it might be a good idea to sit your mother down and draw up a list of friends and family. Perhaps you might find volunteers to help. If they are unable or uncomfortable with going over to your mom's house maybe they might instead be in a position to make and take over and occasional meal.