Hi Rama, my husband is a diabetic and we used to live in Germany just fine.

Try Vollkornbrot - high fiber whole grain bread available everywhere. There is quite a tradition with whole grain - while here, you buy 7 grain hote cereal that "keeps" for month, there you can go to a bakery, buy the 7 grains, and have them grind it to the coarseness you like. THey claim the good stuff is gone after 2 weeks, so they only grind on the spot.

The open air markets are also great.

Stay away from the famous German sausages - actually much of the meat is high fat. Typically, there is low fat cold cut . Tasha's asparagus idea is great. But white asparagus needs to be peeled and cooked a bit longer - you can't eat it straight like green is eaten here.
If you were thinking of strictly made for diabetics things, like chocolates, jams, cookies, your best choice is in a drugstore-like place (Drogerie).