I feel with you Eddie. Probably what's bugging you the most is your health problems. Look on the bright side, you could be hit by a truck tomorrow so all the worrying would have been in vain. Seriously though, there are a number of types of diabetes, most of which can be positively influenced by diet. I don't know which one you are stuck with, but I know quite few people who have similar problems, and those who follow their diet and avoid alchohol seem to be coping quite well. I guess you have tried just about everthing, but if not, try googling for a diet plan(http://www.mayoclinic.com/health/diabetes-diet/DA00027), it doesn't cost anything. Forgive me if I am stating the obvious Eddie, but I don't like to see a good man down. Another help could be the writings of Louise Hay, I've found help there many times.
You have at your disposal however, probably the best medicine anybody can have. Music. Get in your studio and let it rip. Don't try anything new, just roar off some of the old songs you love, give it all you'v'e got until you are exhausted. Repeat that until you wake up with a smile on your face.

Chris