Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Erectile dysfunction in men has multiple causes which include diabetes, hypertension, uric acid and high cholesterol. In your case diabetes mellitus is the chief cause of erectile dysfunction as it leads to neuropathy, your post prandial glucose levels are still high you need to keep them below 180, more over I would advise you to get your Hba1c levels, serum uric acid levels and fasting lipid profile. If any of the above tests are abnormal then get it treated first in most of the cases treating these condition leads to better results and if your labs come out to be fine then start tablet Tadalafil half daily night 1 hour before going to bed. Hope I have answered your query. Let me know if I can assist you further.