I just came across this thread and you seem to be on the same trip emotionally I was last year. We're about the same age, and seem to think a lot alike.
My clear bone scan was the first turning point I remember when the news started to get better as opposed to worse. Congratulations on your positive milestone!
Eveybody is different, but all I can tell you is that you WILL get back to your old self after this is over. This stuff can drive you nuts.... I thought I was going to die by age 47, I'd never see my 14 year old daughter graduate high school, etc.... Natural human nature, but you get past it. My initial numbers sucked, my biopsy sucked, my post-surg PSA sucked, hormone therapy sucks (don't worry about the post surg stuff --- odds are way in YOUR favor you won't have to deal with PSA recurrence!)--- but life doesn't suck, I'm not crazy (anymore!), and I feel good and am optimistic about my recovery... like I said, I sense we kind of think alike --- you'll get to a good place once this is over and done with.
And you WILL have sex again after treatment, no matter what happens.... there's a lot of help in this area --- you'll be fine.
There's more roller coaster ahead, but time fixes this. Talking helps. Faith helps. Time helps. Knowlege helps.
Hang in there, brother... you'll make it through this in once piece!