I am taking lupron on a four month interval. This is called a "depot" injection. You do not say if you are taking the lower dosages with a higher frequency or the high dosage with lower frequency. In either event I have had no urinary infections or problems that I can relate to the injection.
If you have an enlarged prostate this could be contributing to your problem. You may want to ask your urologist about using Flomax. I used it during my radiation treatment and the relief from the burning, urgency, and frequency was within the first week of taking the medication.
By the way, if I may be so bold, I would like to ask if you have considered palliative radiation treatment of your tumors? There is a technology that may be helpful to you and is available in Vancouver, WA and Seattle. WA. I think I recall from a previous post that you are in that area. Do a web search on Cyberknife and Accuray. I really don't know if this is appropriate for you but it can't hurt to look.
Just for the record I am not a medically trained person nor do I have any financial interest in the pharmaceutical or treatment businesses.
Good luck to you, Todd.