HCV, I think anyone who says he hasn't gone through periods where he felt as you're feeling right now is lying. It's normal. This "new normal" takes a lot of getting used to.
Still, your surgery was just 4 months ago. You have a lot of time for improvement. I'm just shy of two years, and I'm still not ready to throw in the towel. You're younger than I am, and your chances for recovery are better than mine. Plus, as my uro told me, we have options, including shots and even penile implants. Not ideal, certainly, but you'll find guys here on the site who are overjoyed that these things have put them back in the saddle. Stay positive, watch the Dr. Mulhall video on penile rehab, and hope for the best. I hope it happens for you.