Can I retire from being an adult?

I work at an on call position at our hospital and a full time position has opened up. I want to apply for it, stop school, and go back to work full time, have insurance again, get a full paycheck again, feel like I'm contributing to our household again. My husband wants me to stay in classes, get my nursing degree, and then work the full time job and have the insurance. I really, really, really want to be a nurse but apparently my homework takes up 98% of my time, work 1%, then kids 1%. Apparently I ignore my husband. I don't see it that way but that's how he feels. I feel horrible that he feels this way and I don't want him to feel this way, ever. He understands that I have so much homework and studying to do and the nursing program is a competitive program to get into but he still feels neglected. He feels neglected enough that he has started an online/texting relationship with someone in a town 3 hours from ours. They call each other lover, send nude pics to each other, talk constantly, and have to tell each other nighty night with lots of x's and o's attached. A month ago he just had to go to this town 3 hours away, supposedly to go to the state fair but now I have my doubts. I know he went to the state fair because he sent me a couple of pics while he was there but other than that he barely talked to me and when I called to talk after I got off work he said he was so tired and just going to sleep early. I believe she was in the room with him. It hurts my heart to think about it and I don't want to think about it but I can't let it go. I only found out about it yesterday so I know it will take a while to get over it. He swears it's over and he deleted her number and information on the computer but I don't believe him. I feel that if I quit school and start the full time position then he won't want to look elsewhere. Of course, this probably makes me sound extremely stupid. If I didn't have so much homework I would have the time for my family again. But, if I continue classes and get a nursing degree I will be financially stable and won't have to worry if he leaves me for someone else because I'm just not enough for him, which is how I feel anymore. I'm just not enough. If I can just not be an adult I could not worry about all this crap. As a kid you can hardly wait to grow up and do what you want to do, get away from others telling you how to act or dress, but when it comes down to it, a boss tells you what to do, company policy tells you how to dress, there is always someone out there telling you something you don't want to do. I tell my kids almost every day quit rushing to grow up because being an adult is not always fun. It's hard work and tedious most of the time, and yes there are lots of times it's fun but it's still hard. Right now I wish I'd had someone tell me this when I was a kid and helped me understand that I needed to enjoy my childhood way more than I did. So, to work full time or be a full time student and get a degree and then work full time in 3 years. That is the question and I have no idea what my answer should be. And what to do about my husband. I don't know that either. When do I say I am enough and make sure I'm mentally healthy?