How do I get motivated?

WHAT A DUMP!

There are three flights of stairs totaling eighteen steps leading from the sidewalk to the front door of my house. Upon entering, there is a living room to the right and a dining room to the left. You are unable to walk into either room without moving boxes or furniture. The dining room table is so cluttered that we haven't been able to sit around it or eat off it for three Christmas'. Half the ceiling in that room has collapsed. The sheet rock, lath and plaster was ruined by a leaking roof which was damaged for years before my husband finally had the roof replaced.
The next room is the kitchen. There is no counter space since I manage to pile anything on a clear surface. There are boxes on the floor because I have no room to store anything in the cupboards or pantry. The floor, surfaces and stove are dirty. I haven't cooked a turkey for three Thanksgivings because the oven is broken. I am too embarrassed to have a repairman come into my house.
Opposite the kitchen is my bedroom. The dresser and nightstand are piled with stuff. I sleep alone in a king sized bed but there is only a quarter of the mattress I can sleep on. The remained of it is piled with newspapers and clothing and other stuff which doesn't belong on a bed.
I can count on one hand how often I've cleaned my bathroom in the past three years. When I was in my early twenties, I kept my bathroom so clean you could eat off the floor. But three decades later I am living in squalor. It took two children, a sloppy, unhelpful husband, running my own business for ten years, caring for my father with Alzheimer’s, being diagnosed bi-polar, depression and obsessive compulsive disorder for me to end up this way.
I have no motivation to improve my living situation. I suffer from this inertia and waste away every day in guilt. I panic if the doorbell rings. My neighbor has reported my outside property to the city on several occasions. I need to get this house cleaned up so I don't die and leave this mess for my children. I live in constant angst over my housing situation.
Today I watched an Oprah program featuring people who hoard from the A&E program Hoarders. My home is not as bad as theirs. But it is all relative in the humiliation we feel. I haven't made an effort since Thanksgiving to do anything except keep up with the dishes and laundry. I need advice on how to get out of my rut.