I'd call your Dr.'s office and ask why they are lying to the disability people.....
Depending on how much your hubby makes you get more than just WIC.... you could get medicaid that will pay for all pregnancy related visits and labor and delivery and after baby could get it as well. You could get temporary assistance with food and electric bills, get your hubbys last pay stubs together and go to social services and tell them your pregnant and need assistance....... Or if your hubby dont "live" with you then just take your last months stubs and tell them your pregnant and no longer working!
I really hope everything works out for you!
Here's another thought. Depending on how much your husband makes, you could apply for WIC. Pregnant women can get it if they qualify. It would at least help with things like milk, eggs, and cheese.
I would be calling the doctor to see why they didn't want you lifting over 5 lbs. I think they often suggest nothing over 10-20 lbs or something like that, but if you have already been used to lifting heavy things, I'm not sure why they would say nothing over 5 lbs unless they detected a problem. I'm not sure...but I would definitely check back with your doctor's office. Also, I'm not sure if FMLA applies in this situation but even if it does, it wouldn't necessarily provide you any pay unless you use time off that you have built up.
In the meantime, I would start looking for another job. I know that's easier said than done, especially if jobs are as hard to come by in your area as they are here. (I'm just trying to think of what I would do in your shoes and that's probably what I would do.) I hope everything works out for you.
Pray able it, don't let it stress you.