I get it, but you already have a job. I assume you are be pretty busy, but at least you already have a secure source of money and you're not against the clock or anything like that.
You don't need to spend all day in a class like a university student. An hour a day dedicated to lectures, practice and taking some notes with pencil and paper* can do wonders on the long term.
As for your wife, maybe you can talk to her and ask her to leave you alone for some specific times, unless it's urgent. Or ask her to send you a message instead of talking so it doesn't interrupt your focus so much.
* Some research on learning has proven that taking notes like that is way more effective than typing on a keyboard.
