The symptoms you describe--frequent urination, difficult urinating and exhaustion--are probably not connected with the prostate cancer. It looks like your husband's is early-stage based on the biopsy result.
If you go with the prostatectomy treatment, they will only do follow-up radiation if the pathology report shows evidence that the cancer escaped the prostate.
A jump in PSA, PSA velocity, is often used to determine whether to do a biopsy and can be a better indicator that cancer is present than the absolute PSA number.
Glad you joined us. Stay in touch and let us know how things are going for you and your husband...Tim