Yup, got the T shirt. Actually had problems off and on before diagnosis, due to bp medication, but diabetes doesn't help. BUT, yes, Viagra does help. Don't be embarrassed, ask your doctor for it, (took me a while to build up to it) you can get a private prescription costs £5. It WORKS. GP was brilliant and supportive. Side effects are little stuffiness afterwards and a feint blue tinge to bright light. There is a 15-30 minute delay in effect which is awkward sometimes but the effects can work for a few hours. I need to add it doesn't give an uncontrolled erection - you have to be 'in the mood' as it were, so no awkward unwanted erection.
I have found that after using it a few times there is a improvement in natural erections, my GP said this is common. So overcome shyness and get some, there is no reason why we shouldn't still have a satisfying sex life. I'm 60 BTW.