gah, please help me to decide what to do with my life 🙏

[Mathstootor]

I have had a safe job with the same company for 10 years. reasonably well paid but still struggle financially as single parent household. I have had a number of medical/disability issues and domestic difficulties and I'm worn out. I am unmotivated and dreaming of retirement. I find my job boring and I don't want to be doing it. I have been considering partial retirement in 2 years, when I am eligible.

I have seen a job that I THINK would reignite me and I would love to enjoy working again. it's less money but my main worry is, what if it doesn't give me the enthusiasm and drive I think it will. then I have left the better paid job that would have given me the option of partial retirement??

WWYD?

In the light of the fact inflation is going to rise, so your costs go up, I'd wait 2 years so you can add 'partial retirement' to your list of options, and meanwhile research things you might do job wise. Do you need extra qualifications to go a rung up and thus extra pay in new job? Any side hustle you can add, given your boring job is so easy you can coast? Any opportunities for promotion or additional tasks, or qualifications you can do within your current company to enhance pay/enjoyment of your job while keeping your partial retirement assets (just in case).
I'd still brush up my CV, look at career coaching (in case something amazing is suggested), and keep an eye on the jobs boards for something more fulfilling and loads better pay.
If you do apply for the more interesting job I would enquire if the pay can be enhanced, perhaps apply - if the hours/holiday/benefit package or commute/WFH is better then it might be worth applying anyway. Even so I'd still ask at interview if more £ would be available.

reasonably well paid but still struggle financially

Is the new job even feasible? If you struggle already, where is the shortfall coming from?

medical/disability issues
Does this require much time off for appointments/recovery etc? Is your current employer supportive and understanding?

Obviously you have the details & know whether you can bear another 24 months of the same shit with the current employer, but the scary thing about jobs is you never know quite what you're really getting into, until you're in it.

My knee jerk reaction to the question is stay & ride the comfy boring train for 2 years.

But it reads that you haven't applied yet, so just get your application in first & buy some time to mull it all over. Nothing to lose doing that.