Hi Steve,
You're right it can be very overwhelming, you get told you have cancer, then there's the realisation of all the side effects associated with the various treatments.
If it helps, I chose the RT/HT route plus brachytherapy which I was offered in addition last minute so extra radiation. I was offered surgery but told it would be none nerve sparing and would very likely require salvage RT later so that was a definite no for me!
I've not had any incontinence or urgency for the toilet and so far the only ED is a result of the HT which will hopefully wear off once my testosterone returns. I do also have a slightly reduced wee flow, starts of fine but kinda trails of a bit towards the end. It doesn't bother me, and I've been prescribed a daily pill of tamsulosin which helps too
Erections are still possible but I'm less enthusiastic about them due to lack of libido. It would be worth asking about tadalafil, it's like viagra, but you take a small daily dose to help maintain blood flow and avoid atrophy. Also a vacuum pump can help to avoid atrophy too as you'll find you no longer get night time erections. Both are available on the NHS. ED can develop over time due to radiation, but isn't guaranteed.
Keeping active also helps, I joined a cross fit club after a feebie 12 week course through Battle Cancer, something I would have ever considered doing prior to all this, it's surprisingly good fun!
Hopefully my message is reassuring rather than adding extra fear!
I was diagnosed aged 48 (T3b Gleason 3+4) and have just finished my 2 years on HT, feeling positive about the future.
All the best John