No, you are not being a baby. You are dealing with a lot right now. Imagine going to work, trying to get your business going, being exhausted, taking care of your family, dealing with your mom and all the other things you do. Then add to that the fact that you went against your husband's wishes because you thought you could read his mind. Not a great scenario. You would not be the wife and mother that your family wants and needs.
As a mom, your first instinct is to be there for your kids. Your husband is very proud of the fact that he sacrifices for you to be able to be the good mom that you have been. Do not take away that pride from him. Go back to school. You will have the freedom to attend to your kids' activities and be there for them.
As far as your business is concerned, you need something to kick start you into really being passionate about it. Watch motivational videos, listen to motivational messages online, etc. Find people who are good at what you do and start doing what they do. Be excited about it! Sell it as the best thing ever! Don't worry if people think you are nuts; some will catch the excitement. Schedule time each day to focus on your business. Is there something your mom can do to help with the business? If not, ask if she's ever thought of finding "a fun little job," working part-time at a bookstore or craft store (or whatever her passion is). If jobs are hard to find where you live, see if she'd like to get out and volunteer somewhere. She is probably bored and not feeling like she has a purpose. But don't come out and tell her to go get a job. It sounds like she might resent you.
Go out of your way to pamper your husband to show him how much you appreciate his desire for you to be happy. Everyday when he comes home, be the kind of wife that you would want to come home to. Then he will never regret his decision to have you stay home. (Even if he secretly desires for you to bring in some money.) What he is actually telling you is what he has decided to tell you and the way he wants it to be. What a great guy!