Suggest Treatment For Erectile Dysfunction

I'm 25 and I can't achieve an erection for very long, or without direct physical stimulation. I had an anal fissure 2 years ago that took over a year to heal and I'm still having problems with it. I also have degenerative disc disease. My libido and sexual functioning were fine before the fissure. Is there anything I can do?

I'm healthy, exercise 6 days a week with excellent blood pressure. I'm in near perfect shape...not sure what the issue is here. It's very depressing.