J.S.
I'm answering based on my own thoughts here, without reading what anyone else has written. I went back to work at the end of October after being a stay-at-home-mom for ten years. I started looking for work two years ago when I was ready to look, and got help looking for work when I was ready. Because I have a disability I ended up going to the Bureau of Rehabilitation Services so they could help me with a job assessment, and the place where I did it ended up loving me so they requested to have me placed with them. That's where I am now, permanently.
I was nervous for all of the reasons I'm sure you're nervous. I went back for all of the reasons you're going back. My children are all in full time school and my autistic daughter is well established with her IEP and learning to self-advocate. We have other issues with my eldest daughter hammered/hammering out. I feel confident that with an understanding employer (and I did find one! yay!) this can work.
None of this has been up to my husband. He was part of the decision making process WITH me but he didn't order me back to work, and if he's ever uncomfortable with me working it won't be his decision for me to stop working. I know that with my particular disability that there will come a time when I'll have to stop working, but that will be decided between me, my doctors, and my husband. It won't be decided for me.
If you want to work, then work. If you become established in a job that you enjoy and it works out for everyone except him to the point that he creates problems, that's something that you have to discuss with him. He may be proud that he can provide everything you and your family need. That's fantastic. And you feeling like you want to contribute financially is great... but don't you dare downplay how you've been contributing. You've been contributing to the family at least as equally as financially would be if not more.
If you think working would give you some play money and/or be nice to have in your own account and/or just be nice to get out of the house, there's nothing wrong with any of those things. It's not selfish. Happy mother, happy wife equals happy home.