My rule of thumb is that there is very little point in planning for things that occur >5 years from now. Priorities change, external factors change, and so on.

That said physical health is maybe the single exception.

Sounds like you don't have 2 free days a month anyway seeing as you're incapacitated by the back pain to begin with.
The 35h is a false premise of it comes with debilitating pain

Insurance companies like hiring nurses. Adjustors who understand medical terms and conditions do very well. No bachelor requirements

Most corporate drones that I knew eventually wanted to throw it all away for an outside job of physical labour. That's how empty, soulless and dissonant corporation work becomes. I was one of them.

The union should demand better equipment to protect its members. There are bed lifts and training to use them that should be included in your job.

20% pay increase for a 12% time increase. Honestly, those numbers aren’t big enough to entice me on their own.

But I think the bigger thing is job satisfaction. In your current job you spend 35 hours a week doing something you hate. Would a PA mean you’re spending 39 hours doing something you enjoy?

I would focus this more on your happiness than economics. Being miserable has no money associated with it but it’s the thing that follows you around 24/7.

If you just want to get away from bedside, you might want to keep shopping around for other degrees you think you’d like. If being a PA is something you know you’d like (never mind the 39 hours - just the tasks the job itself entails), that seems like a smart path to follow!

Laughing at myself for working 40+ hours like a chump

How do I decide if I stay at a 35 hour per week job that’s breaking my back or start studying a bachelor to work your regular 39 hours per week but earning 20% more than now after I finish it?

You may benefit from a cost benefit analysis.

but 39 hours per week, till I retire… I don’t want that.

Whereas you do want backpain for the rest of your life??? If you've seen a physical therapist, and this is still an issue, I think you know the answer.

39 hours a week but it's not taking days away due to back pain. It sound like you can't do the 35 hour a week job so I'm not sure why you're using that as a basis. It's gone, mourn it, and make your decisions.

I jerk guys off behind a dumpster for cash. Need strong wrists hours flexible.

2 extra days a month aren't going to mean anything if your back is too screwed up to enjoy them. I'd easily lose 4 hours of free time a week if the trade off was pain versus no pain.

The 20 first years of my life I never really stood up for myself.

Work isn't everything in life.

Life itself is so much more than work. Even as someone who likes to work I say that.

Think ahead a few years: Will you have a really ruined back or not? That is the bigger question IMHO.

I'm afraid that quite a lot damage is already done, and will become apparent only later. But the coming years from now on are still very important. Either you stop the ruining now, seriously, or not.

I recommend to think about what is best for yourself.