I'm so sorry for everything that's going on....hugs!
I don't actually believe their has been a strong association of stress levels to worsening bladder incontinence issues, stress can worsen fatigue and make any issue feel worse but causation is more the point with neurological conditions.
Whilst I really do want to encourage you to put your negative Urodynamic testing experience behind you, problem is i understand the avoiding part so i kinda feel a bit hypocritical encouraging you to put your big girl panties on and just do it....when my big girl panties are stuck hanging on the line.....
Dealing with the workable solution is another matter entirely, one step at a time, the Self-catheterisation solution you have in your thoughts may not be necessary and an alternative solution better for your at this time......
Ask your self, if going through the Urodynamic testing will get you closer to finding a workable solution to the problem? If the answer is yes, that's definitely encouragement worth focusing on to get you through it again, right?
I'm in the same boat - may have to self-catheterize soon, as I have retention and incontinence. No advice, just sympathy!
All I can say is, I couldn't imagine self-cathing. My primary promised me it would become incredibly easy and I trusted him. (Emphasis on become, lol -- not neccessarily easy to start). I also had to have an indwelling catheter for a while -- no picnic, so given the choice between indwelling and self-cathing, I learned how.
It became easy. I did have a really good nurse come to my home to show me how (don't let anyone teach you to do it lying down -- just not possible). Try and start with a small catheter size - much easier when you're starting up.
You can do it!