Hi PBH and Welcome to the Forum!
Don't be surprised if you have more than one condition and they are adding up to make you feel physically and psychologically miserable. In addition to getting all the diagnostic work done to check for PCa, make sure your uro is addressing all of your issues, at least to ascertain the cause(s). If not, don't hesitate to add an internist or other specialist. When you have a little more info as to what's been diagnosed or ruled out, other Forum brothers will be able to help you based on their knowledge and first-hand experience.
As far as PCa is concerned, it's very easy to be overwhelmed, especially at first, when trying to do research. I suggested simply waiting to see whether or not the imaging shows anything suspicious. Keep in mind that many uros will still want a baseline biopsy even after a negative MRI if they still suspect cancer. IMO, if your trust your uro and he or she wants a biopsy, get the biopsy. If you don't trust your uro, find another.
A baseline biopsy can be useful whether positive or negative. If positive, it will tell you the risk level of the cancer. Many low-risk men can manage with active surveillance (AS), which can either let your delay treatment until your risk level increases, or even get through life without having to ever treat the cancer.
A negative biopsy -- while not being able to rule out PCa completely since it examines a very small amount of prostate tissue -- can give you peace of mind for the time being and will serve as a baseline for future imaging or biopsies if they become necessary. A negative that biopsy checks any areas judged as suspicious on the MRI gives you even more info.
Lastly, a positive biopsy showing you have cancer and are not a candidate for AS will let you narrow the focus your efforts on treatment suitable for both your risk category and the specifics of your cancer and status. This becomes a much more manageable phase since the decision tree is much narrower than searching for "prostate cancer" and thinking you need to gain a urologist's knowledge of the disease in a weekend
So the diagnostic tree is pretty simple at first: (1) no evidence of prostate cancer; (2) low-risk PCa that is a candidate for AS (if you so choose); or (3) more serious cancer that requires treatment or low-risk disease that you choose to treat. Most men who get treated put PCa in the rearview mirror.
If your diagnosis includes BPH, we can discuss that, too, in the Forum. In the meantime, if you are worried about
urinary retention becoming severe, my advice is to stay close to home and postpone any longer trips.
Please keep us posted, and best of luck!