There are bad managers everywhere :-( Sometimes you can't avoid them and have to endure it for a while.
University education has become a scam run for the benefit of faculty and staff. I was asked to sit on an external advisory board at my alma mater. All they actually were interested in was my money. I stopped giving them any.
If you feel you would benefit from a formal course, do that. The fact that you are working and taking a formal course demonstrates your drive. That has value with employers even if the content is not relevant to their needs. The piece of paper may or may not matter. It's just a recommended structure. But don't go into debt for a graduate degree. Buying and reading books is cheaper and the schedule much more flexible.
Getting a BS you learn how to learn. In an MS you learn something. With a PhD you acquire the ability to teach yourself.
The most important thing I learned in grad school was that you do it the first time to learn what you're doing, the second time to learn how and the third time to get it done. If it's critical to your dissertaiton, you do it once more to make sure you got the same result.
If you observe that there is an area at work where you think your skills are deficient, buy a book or two on the subject and read it. If you find the subject matter difficult, read it once or twice. If the writing is bad, buy a different book and read that before you reread the first book. If you always have such a book that you are reading and you read 4-6 of these a year, when you go for an interview you have a great subject of conversation that demonstrates why they should hire you. It also means that if someone doing that work leaves the company, you are likely to get the job.
I'll close by noting that most of my jobs found me rather than me looking for them. And they sought me, by name, because I have 80 ft of computer books in my library. No formal education other than a 1 hr WATFIV introduction to FORTRAN programming course. The books cover everything from CPU design (Computer Architecture: A Quantitative Approach) to algorithms (Knuth & Sedgwick among others) to software engineering (Code Complete and numerous others). Excpet for a BA in literature, all my formal training is in the sciences.
Read essays by and about Jim Williams, Bob Pease and Bob Widlar. Keep a sense of play. If it gets tedious, read something else. Most of all,
Have Fun!
Reg