Papa, welcome to this forum which is a good place to chat about your fears or anything prostate related.
Very early days for you both in terms of tests and potential diagnosis and also in having enough information for any medical reassurance or otherwise.
Firstly I would say as a confessed hypochondriac 'stay off Google searches' they are far too generic and would frighten a saint to death!
Secondly, if you feel happier at this stage dealing with things yourself that's fine, a few men on here have regretted doing that as things moved on so I'm sure at least one will post back to you on that bit.
Thirdly, an enlarged prostate is quite common as a man enters his 70s and there are a number of things that can cause that which are not prostate cancer. Your PSA at 5.4 is elevated for a man of 74 but that can also be caused by other conditions or factors.
If the sharp back pain has been positively confirmed as a hernia then you probably need to work on that basis just now. I am not entirely sure why that would stop any further diagnostics on your prostate symptoms though. Frequent peeing and an enlarged prostate could be symptoms of an infection like prostatitis, that can also give lower back pain a urine infection can do that too.
It is very hard for a woman to put herself in your shoes but if it were me I would return to my GP after the holidays and ask for a further discussion. Ask about infections, did the prostate feel smooth and large or lumpy and large? Let him know you are concerned and would feel happier with a more conclusive plan of action ahead.
Meantime try and just enjoy your Christmas.
If you are travelling to see friends or family and this goes for all of you out there, travel safely.
My very best wishes
Xx
Mo