Welcome to HW -
Based on other conversations with my uro about my own situation, I believe he would have you off any T-supplements immediately.
I've also seen a lot of discussion that T levels can't predict future PCa, but once you have it (and a Gleason 5 is the worst), I believe you have to do everything possible to help kill it.
I was G 4+4 at biopsy, and at that the surgeon said there would be a decision to save the nerves only during surgery, and the post-op path confirmed that the capsule had been broken, so it was the correct choice to remove them. The important thing is to be working with the very best surgeon you can find (if you go the surgery route), as you will be trusting him to do what is needed to kill the cancer while leaving you a good quality of life while the surgery is in progress.
You will also want to talk to specialists in seeds and IGRT - radiation methods can be combined now. I was turned down for seeds as well, but I didn't accept it as definite until I had an opinion from MD Anderson.
I'm also single, and at best I can say that you will develop a "new normal". Being alive leaves options, but as the book title says, dead men don't have sex.