Hello there Andrew, and welcome to the forums!
I'm glad more and more people are joining along with the same passionate aspiration of developing their art. Unfortunately, back when I worked on a different field than art ( web developer, ugh ) I had a similar case, where my work would go to waste on deprecated code and old hard to maintain software infrastructure. 0 opportunity to improve, thank god I resigned and started taking art seriously, I couldn't see myself there for any longer.
It's even more intriguing reading your intro, since similarly, one of the many main motivations for taking art seriously was to start tattooing! Though as the months pass, I'm still exploring where art leads me. At least I want to polish my fundamentals before going into tattoos.
Finally, your sketches look nice, and you got potential. Keep practicing the exercises of this term, gesture drawings and the pen control exercise will help you make more confident lines as the times passes. For less shaky lines, try to learn how to use your shoulder more when you draw, and focus on the line flow instead of accuracy at first.
Keep it up Andrew, I'll do my best to keep in touch with your updates!