Sorry to hear Archy is having problems. It is always a worry when a middle-old age male cat is having
urination problems as there is a high incidence of crystals in the urine in this age bracket. there are more of this type of blockage or partial blockage in male cats than bladder infections.Overweight males are higher risk.
Try to have a litter tray available at all times so during bad weather or other times when outside access is not available ( hospitalised at vets or strict rest for injuries ) or weather is off-putting ( cats are originally desert animals and hate cold, wet conditions ) they don't hold their wee in too long and cause problems. I know some people don't like the idea but it can prevent stress or medical problems developing.
A big pottery dog bowl is ideal for drinking, and tinned food is approx. 70-80% water so keep him on this until your vet has checked him. Keep a close eye on him when he toilets ( another good reason to get him used to a tray ) Any amount of straining and not passing urine over an hour or so could mean a complete blockage and present an emergency situation. Don't delay to contact the vet as kidney problems can be the result of a blockage left too long.
I hope it is just an infection for Archy although it probably doesn't feel like JUST to him, poor lad.
he is on the mend soon. Let us know how he gets on.