I've tried:-
Cialis (useless)
Viagara -- worked but eventually didn't. Apparently you do become resistant to it.
Levitra - useless.
I now get Viridal - which you inject. Is painless, easy to use, and very very effective. Lasts for an hour or so. No side effects other than sporadic involuntary erections for 3-4 hours afterwards. But who's complaining.
Below - for any interested parties, is a photo of the applicator and a cartridge pack. There's an oxo cube just as a reference for scale. If anyone is interested and considering asking their clinician for it I'll make a short video clip of how quick it is to assemble it etc and forward it to you. After using one, I immediately prepare another so that reduces prep time even further.
If you are considering it, you will need to ask your Doctor/Diabetes nurse to refer you to your ED clinic. They will show you how to use it, let you try one, check the dosage and four hours later you phone them and if there are no adverse affects you get a note for your surgery to add it to your monthly prescription. You get one a week unlike the tablets (which are two a week) because it is obviously more costly.
Don't be bashful guys. It works and it's worth it.