Fascinating! Have you ever considered using a tablet, just for the sake of protecting your wrists? Most programs (especially free software like Gimp) let you turn off pressure sensitivity if you still want that “drawn by a mouse” look. I personally use a tablet now instead of a mouse even just for checking emails and such, you have no idea how convenient it is to just swipe up and down long web pages like one would on a phone!
Your art has definitely improved a bit since then. I have some suggestions for your current style, but I know most artists on the Internet just do art for fun and thus I’ll keep quiet unless you specifically ask me for feedback.