Quite a difficult decision. The starting point is are these symptoms actually to do with the HT or just coincidental?
Can a different HT solve the problem?
Can the symptoms be relieved with other medication, paracetamol?
Of course all the above you have thought about.
Next thing to consider is quantity and quality of life. You're 78 how long do you want to live and what do you want to die of? Now the answer might be I want to live forever and I don't want to die of anything. Well that option isn't on the table.
If you stop HT you might get three years of life with only your other comorbidities to deal with. After that cancer will probably start to take over and dwarf your other comorbidities. You might live another two years, and have a few other treatments so you would probably die at about 83.
If you stay on HT you will have the side effects of HT, but you will probably get to 83 without the complications of cancer, after that well you might become HT resistant or another comorbidity will get you anyway.
The above timescales are just guesses, you may get longer or shorter on any of them, but I think the timescales I have quoted are reasonable averages.
I don't know the answers for myself let alone you. If you don't try and avoid the question "how long do you want to live and what do you want to die of?" You might find the answer for you.