What Is The Treatment For Erectile Dysfunction?

I am 56 yrs old and have been diabetic for close to 15 years now. My problem is that my random sugar after meals may shoot to as high as 200 or almost 12.0 but show a fasting of about 120 or 6.7 when on 3000mg of metformin(glucophage), 10 mg of daoni and 30 mg of pioglitazone taken in divide doses of morning and evening. Of late, about a month ago, i have been intorduced to galvusmet (1000/50)+5 mg daonil twice a day and the effectiveness has been remarkable. Fasting less than 90 and random 150. Recently, I have reduced the dosage to 500/50+5 mg of daonil taken twice a day and the sugar level has held at 130 random and 110 fasting. The side effects I have noticed has been incessant stooling and svere constipation. Would this be as a result of the change of medication? If yes, what should I do. Another problem is that my libido and erection has quit completely even though I still desire to have fun. The popular viagra and cialis don't seem to work for me. I need your advice on the erection disfunction please as well. Thank you.