lake Would you quit your job under these cirstances?

I'm getting to the point that I don't want to go to work anymore and it's worrying me because I am only 27. I have been at my job for over eight years and I'm not sure If I am tired of my job or just tired of working in general. I'm not a lazy person by any means but I feel worn out. Recently, my boss fired 2 of our office employees (cutbacks) and have put a good portion of their work on my plate. He said that he wants to add to my workload because things are slowing down due to the economy. This is fine, but my duties have yet to slow down and he is putting pressure on me for these new responsibilities that I am having a hard time finding extra time for. I already run his office and his rental properties (separate from his business) and I manage one other employee. I feel overworked and I feel like a paid slave. The other thing that irks me his wife who has nothing better to do, makes me do her personal stuff stuff like deal with her personal insurance problems. I have to pretend I am her on the phone, which I hate. I feel this is out of the question because I was not hired as a "personal istant" although I feel like one. She used to have me watch her kids constantly and help her clean her house and I would get yelled at by my boss for not being in the office enough. I hate when she asks me for anything anymore. I just want to scream at her and tell her to do something for herself for once. She doesn't even work. I would so quit my job if the pay wasn't reasonablly good. If I leave I will likely have to take a signifigant pay cut and I am used to living on what I make now. I'm trying to decide if I should "spread my wings" and work somehwere else regardless of a pay cut. Anyone else feel this way about their job?there