You can do it! I agree with the other poster to do a trial run first... but trim your expenses first. Staying at home takes lots of financial sacrifices, but it's so worth it! Others have had similar requests like yours recently.... here's my response to one a few weeks ago.
If you're serious about wanting to stay home... big sacrifices have to be made for that. Sometimes we put ourselves deeper into big expenses than what we should. Just because we can afford something or we have the money to buy a bigger house or car, doesn't mean we should ..... please, that's not to say that's what you're doing. This is a lesson I'VE learned in my finances. And the discipline hubby and I had to learn in order for me to stay home.
We've learned to live WAY below our means so we have extra money to save; pay cash for big emergencies or unexpected things that come up (no charging credit cards anymore!); paying cash for big things we want (a vacation). Because our expenses are below what we're bringing in -- there's much less stress at home. When you live WAY below your means -- there's no need to worry about will we have $ for this or that b/c you're building your savings every month.
We live in a smaller, older home ... drive moderately priced cars. My husband bought a no-frills (no bells and whistles added) car recently. We have the same old TV we've had for years. Have the basic package on satellite - only one satellite TV in the home. Lowest priced plan on our cellphone. No cleaning lady. No dry cleaning bill - I iron everything. We eat out only once a week. I cook/prepare every meal - easier on the pocketbook. Even though we CAN buy all these extra things and we would like to ... we don't.
Ok.... so that's just my story. When we finally made the decision to go from 2 incomes to 1 - we were serious and we did drastic things. Lived in a one-bedroom apartment; no cellphones; drove old paid for cars. You said your car was cheap but what do you define "cheap". I define "cheap" as paid for in cash -- like that much cheap. Like NO car payment. What about hubby's car? His could be a paid-for older car, too.
We did the trial run of living just on hubby's paycheck and dumping my whole check into savings - we did this all during my pregnancy. And through this we learned to adjust to a more frugal lifestyle.
Also... you might want to consider rearranging your home living expenses. If you live in a home, consider selling it to buy a smaller home with a smaller mortgage payment. That's where the majority of expenses go to - a big mortgage payment. But i don't know your situation - you might be renting already.
Just examine every expense ... and really consider - can we get a smaller one of these - or do w/o it. or get an older one of these? Or sell this to get cash for it to help pay down this.
But my guess is that if you are $800 in the red (when you live off hubby's income) then you might have a larger expense that can be trimmed down or traded in.
Again, like I said -- drastic things need to be done. We had to do this, too, and it was soooo worth it! I love staying home w/my son. These first years go by so fast and I don't want to blink to miss them. We had the rest of our lives to buy big stuff -- but only these first few short years to stay home w/our kiddos. And the kids don't care what cars we drive and how big the home is. If they have a voice, they'd say - I want Mommy here.
*I remember when i was a child, i had a friend whose family wasn't "well-off" financially, but her mom was a stay-at-home mom. I asked my Mom "why can't you be a SAHM like (friend's) mom?" and she would say "because we can't afford it." As a child, that didn't make sense to me. Why could they afford it, but we can't? But looking back on it, I can see now that my parents had placed themselves into deep debt and high expenses so the NEEDED my mom to work. My parents took lavish vacations and shopped a lot -- so the credit cards bills were high; they drove new cars all the time -- they never drove "paid-for" cars. They always had a car payment. They never kept a car long enough to pay it off. anyway... my friend's family -- I can see now -they didn't have those high expenses. They drove older, paid-off cars and bargain shopped. And ordering pizza on the weekend was a special thing for them. We ordered pizza 2-3 times a week and ate out a lot because my mom was tired after work and didn't have time to cook by the time she got home. anyway... I can see now that if someone who's living on a lower income than what my Dad was bringing home at the time...if they can do - so can I. I just need to live like they did.
Good luck and you can do it! It is a leap of faith, but that's part of maturing -- to take these risks for the benefit of your family. Being disciplined to put your priorities in order - and letting that reflect in your checkbook/wallet.
Just keeping thinking that LOTS of moms/families do this - go down to one income (and not all of them are rolling in money) - if they can do it - so can I and I will because my kid(s) deserves a good effort from me!