what are the drawbacks to having a seat in the shower if you can't stand for long?
if you have misgivings about tramadol, then you need to look to more simple painkillers.
i am still not sure if you have given them a good go (of at least a week) because you tend to become a bit cagey, which of course is your prerogative. However, if you dont want to take opioids or amytriptiline or gabapentin then your options are limited
my advice, which of course you are welcome to not take or to take is to start with paracetamol 4g per day. then add in ibuprofen (i'm with sqad in that gel/cream is rubbish compared to taking 3x 400mg per day). if that regimen is not doing the trick then add in you dihydrocodiene. then you'll need to increase the strength of the opioid if thats still not working - ditch the dihydrocodiene and add in the tramadol 100mg 4 times a day.
you need to give that a good go before increasing to a stronger opioid