First of all, some people learn better in a structured environment and some do not. I learned pretty much every programming language I know from books and practice on my own. But, not everyone works that way.

I've worked with a pretty good range of programmers, and trained or mentored a few of that set. It seems that most of them improved from two practices: reading code and writing code.

Any time you can, read code. (The Monastery is a good resource for that.) It doesn't matter if the code is great or not so great, learn to understand other people's code and judge good code from bad code. This is one thing that most degree programs don't spend any time on.

You also need to write code. If you don't try it out, you won't really learn it. You don't always need to write huge systems to learn. Quite a few skills come from writing little pieces of code to make your life easier. (Unfortunately, working on really large systems needs different skills. But, you can learn them later.)

How you do these things is (slightly) less important. You don't really have to eat and sleep programming to get good at it. But, you also can't expect to get good spending 30 minutes a month. I believe you can improve with dedicated study a few times a week. But, you may need to allocate some time to work an uninterrupted period every now and then to really burn in some of what you learn.

Unlike the bicycle example, if you stop coding for a couple of years, it will take some time to get back into it. You won't lose it all, but it will take some practice to get your old habits and ways of thinking back.

The family and degree thing can be quite challenging, as I recall. Focus and determination (and a lot of support from the spouse) really helps. One important thing to keep in mind about the degree was best said by Mark Twain:

I never let schooling get in the way of my education.

Good luck and stick with it.