Has anyone been in my shoes or close?
It's very possible to do, but will take some discipline. I was taking 12-14 cr a semester starting out. I buckled down and started taking 16 cr a semester because I wanted to get into an undergraduate major/program at my school that only accepted a handful of students per class.
This past year I started the 1st year of the program and was taking 19 cr a semester (all classes 300+ level), with a full-time job (sometimes OT), 2-3 tests per week, and I had outside duties as a secretary, ambassador, and president of 3 different organizations. I'm also an independent student (hence the full-time job), married but no children. I got very little sleep, hated myself some weeks, and know this is still going to be my life for a little while, but gosh darnit, it can be done.
I had poor to average time management skills before entering my new program, but after orientation week when we started our classes, I realized it was time to shape up or ship out. I started planning things way ahead of time, studying whenever I could slip some time in (lunch breaks, work breaks, etc), and I cut off most of my social life time down (started hanging out with people not once a week, but once a month). Ended up getting 9 As and 1 B.
I know this other guy who is Pre-Med who's amazing. He's in his late 30s and went back to school after he and his wife became financially stable. They have 6 kids, both work full-time, and he just graduated with a 4.0 and was involved in several organizations and internships, etc. But he had a hell of a lot of sleepless nights, missed his oldest kid's graduation, and had to forgo many family vacations. That was his decision, though.
But, everyone so far has given you pretty sound advice: Take it slow, know your limits, build up if needed, and if taking more classes actually helps financially (at some places you get discounts after taking X credits in the semester, etc) then fully consider that. Your experience is different from anyone else's, so you just need to keep in mind how much time you want and/or need to dedicate to each of the responsibilities present in your life.
Good Luck! If you give it your all, you will do great
🙂