Should I leave? What would you do and how?

My husband and I met each other when we were 20 years old. We were friends for 3 years before we started dating. When we finally stated seeing each other we had already become like best friends and moved in together pretty much immediately. That was 17 years ago. The first 10 years flew by, we didn't have any kids and we went out, we had adventures, we moved 2000 miles away from home and started a life together. We bought a house, started a business, struggled through bad times, lived paycheck to paycheck, and still managed to get along. We eventually started doing better financially and decided to stop trying to prevent a pregnancy, we had never really been all that careful anyway. We didn't have any "scares" in ten years so I kinda figured that it wasn't in the cards but we both knew we wanted kids "someday", I wasn't getting any younger, blah, blah, blah...well I ended up getting pregnant within a month with my son, followed 16 months later by his little sister. I had been working the office side of our landscape company for years from home anyway so it was an easy adjustment into stay at home mom...or so I thought. Since the kids got here our life has fallen to crap along with the economy. We had always live pretty hand to mouth before, but in the last 7 years its been pretty bad. We bought an investment home while things were looking good and fell into the trap that a lot of people did with the real estate market. We have since lost our home and had to move into the investment house. Our landscape business went under and my husband has been trying to start a small custom car shop out of the barn in our backyard. Its going okay but not exactly paying the bills and now we are about to lose this house too. We are way behind in the mortgage and hardly have enough to pay for groceries most weeks. I have thought of trying to find a job but there is no one to help with the kids, the nature of the business is that these guys come over in the evenings and they work on the cars throughout the night. My husband continues to work through the day and he rarely is even in the house. He really only comes in to shower, eat, or to sleep. I go out to the shop and he only wants to talk about cars, racing, or what I'm doing wrong with the kids. I knew when we had the kids that they would be mostly my responsibility but I have been left with them with no escape since the were born. I really am only away from them to maybe go to the corner store real quick. Its been a real struggle, I have let my "office" responsibilities go to nothing. There is pile of paperwork in our office about 5 years deep. Frankly I was overwhelmed with my son and since my daughter came I'm just lost. My son just turned 5 and has been in preschool this year which is kind of a respite but by the time I take him to school and drive home it seems like I just turn around and go get him again. I can't concentrate on anything, there is always a little voice in my ear asking for something from the time I wake up in the morning until I put them to bed. I have tried to tackle the paperwork innumerable times but I only get to a point where I've sorted stuff out and am ready to start working when its time to get do or help one of the kids. I could be more diligent but I haven't been yet. Between the kids and my husband I feel like i'm being harrassed ALL THE TIME. No one eats anything in this house including my husband it seems that I dont have to hand to them, no one else does anything to keep the place clean, i do all the laundry. I know I don't work so thats my responsibilty but I am feeling like I don't get anything out of any of my efforts. I don't have a car, I don't get to go anywhere besides the grocery store, we moved away from my family and I concentrated on the business for so long that I never really made any friends down here and it seems have forgotten how. I have met a few other women over the years but my husband always had a problem with them for one reason or another so I chose him over them. At this point I'm very overweight, I have always struggled with my weight and confidence and my husband is an ex jock and very in shape and very outspoken and confident. He is brutally honest and doesn't hold back when it comes to telling me whats wrong with me. I get told what to do, when to to do it, and then criticized on the job I did about everything I do. I know that he is under stress and I'm his only whipping post but it has really effected me. And he doesn't seem to care. I know I'm not perfect, he doesn't expect me to be perfect, but does expect to keep trying and to be honest I'm tired. I am tired of hoping for things to get better. I'm tired of being his whipping post. I'm tired of having someone crying at me and of feeding people while struggling not to eat too much. I'm ti