Sounds like your treatment plan is very similar to mine. My daily dose was 180 cGy for the first 30 days for a total of 54 Gy. Followed by LDR Brachy. I have to additional treatments left to be completed in March for an additional dose of 18 Gy.
I had no urinary issues during the DART teatments. I have had some mild issues since the LDR Brachy but they are improving by the day. I would suggest you discuss your urinary issues with the nurse.
As far as the headaches and congestion I also had none. The carafate was my biggest problem and it caused nausea and vomiting until I cut back on the dose. The headaches and congestion could be more related to the hormones, but I did not thae any so I cannot say for sure.