This situation sounds trying and hard. This is your grandmother, not his. So I can assume your hubby likes having spending money each month. Since it's cheap to be there he has a LOT of play money each month, you do too? Put your money to a good use. Pay for some classes or child care and get out doing stuff, away from grandma's house every single day.
He's not your father or mother. If you want to go to work then go look for a job. Find out if you can get child care assistance to pay part of the child care bill for the new baby. If you want to earn money there isn't anything he can do. If you filed for divorce he'd get custody since he is working and can support his children. You wouldn't be found fit since you'd have no income.
I would let my husband know that this isn't working and that you are not happy.
I would assume that Tennessee has a similar income/housing cost as Oklahoma. We paid $18,500 for a 3 bedroom, 2 bath mobile home and lived in it 12 years. We paid $40K for the 4 bedroom, 3 bathroom, 2 living areas, dining room, and study area home that we live in now. It was off a mobile home lot, used, but in good shape.
Mobile homes are not expensive, they are hard to heat in winter and cool in summer if they're not sealed well though. You do have to have the land set up/ready for a home. Either sewer hook ups dug and installed or hooked up to a septic tank. Your own septic tank. Then you have to get your own pole for utilities and a propane tank. Unless you're in city limits and then you just dig water lines, still get your own electric pole, sewer lines, and a new gas line with your own meter.
Preparing the land can take up to $10K. Depending on permits, where you are in regards to a city or in the country and what you have to pay out of pocket. We had to put down 12" wide/18"-24" deep runners that were at least 30' long before out current home could be delivered. That cost $6000. Then we got our own electric pole hooked up, it was already there. Had to pay an electrician to come do all that after the city put their new meter on that pole. Had to hire a plumber to come out and dig trenches for the propane tank lines and the sewer lines to the existing septic tank. That cost us about $4000.
Our mobile home was used and off a lot so they paid all the moving and set up on the first one. the second one was buy as is. They didn't pay anything except to put the 2 halves together once it was here. We paid $4500 for it to be delivered.
All together we paid nearly $20K to get our current home here, set up, leveled, tied down, on the runners the right way, etc...my husband got an inheritance and we spent it getting a home and paying cash for everything.
It's not hard buying a mobile home. You do need to consider all the outside costs that go with it though.
A couple of things. Mobile homes need yearly tags if they still have axles. Make sure about that. We paid about $500 per year for insurance on our first one. It was good coverage too. Payments for a mobile home might run a few hundred per month. Ours was bought by my mother in law so we had no payments. Maybe grandma will buy the home outright and put it on her land and she will retain ownership. You guys could do an intercom deal where grandma can alert you if she needs help.
Overall a mobile home is easy to buy. Everything is in the purchase price from a lot. Delivery, set up, taxes, everything. If you buy from an individual you'll have to pay for tear down, delivery, and set up. That can cost a couple thousand per section.
You CAN go to work without his permission.
You CAN look at used mobile homes and see what's available.
You CAN talk to your grandmother about this and see if there are any options she can think of. She might be ready for you to move out too.
You are an adult and can move forward as an independent wife, mother, granddaughter, and more. It takes deciding when enough is enough. Your husband is not your boss, he's your equal. Since he's making the money he probably thinks his word is your order. Stop that. He is your spouse and your mate, not your caretaker.
There comes a time when you have to decide what life is worth, what it's about, if you are living or surviving. It sounds like you are simply surviving and not living at all. Make slow progressive changes. Finding a way to make money for yourself isn't bad.
Do you sew? do crafts? bake delights? have any marketable skills? Find out if there are any online programs you can do that will be a home job for you.
Go to school and get a license to cut hair or do nails. Fix up an area in your home or fix up grandma's garage where you can have a sink, chair, and mirrors so you can take in customers. Take the baby and put them in a sectioned off space where you can see them and spend time with them when you don't have a customer.
Do taxes in your home. It doesn't take a lot of schooling to do that. There are simple forms to fill out and they do the training.
There are many things you can do and still stay home but going out into the world and making friends, going to classes, being out of the house for even a few hours per day will help you immensely. Looking at the same 4 walls every day will drive you nuts, I know, I've been there. We lived with his parents for a while when he got laid off of his very lucrative job. His mom would come in, take "his" laundry-wash it, iron it, hang it up. Mine? She washed and dried them put it in sacks because she didn't know how I wanted her to do my clothes..less wrinkles would be good, right? She would come in and sort out our drawers, my underwear drawer! For goodness sake!
And I LOVED her dearly, she was the best mother in law in the whole world. I miss her every single day. But living with her? Not so much.
You need to be out of the house during the day. Either find friends where you can go and hang out, go out in the world, take classes, do something for yourself and get a babysitter.
Find a Mother's Day Out. They are usually at the local Methodist Church. We have 2. One is M-W-F from 10am to 3pm. We take their lunch. They eat lunch then nap. From 6 weeks to school age. The other one is T-TH and 9am-noon. They don't eat lunch and come home for lunch and nap. Age 6 weeks to 4 years old. MDO is not child care...they don't have to have licenses because they're only part time. You only pay for the days your child is there. You do enroll them so they have the right amount of teachers and classroom supplies but it's not like child care in lots of other ways too.
You can move forward and make your life better even if you don't move right away. YOU can be happier and mentally healthier if you simply get out of that room all day every day and don't spend time there except bedtime.