Hi Connie.
My sympathies, sounds awful for you.
I was diagnosed 5 years ago with PAD just after a T2 diagnosis.
I had already stopped smoking but that had undoubtedly caused problems over the years.
I had also put weight on pre diagnosis.
Walking had become painful, Calves particlarly (which is typical of claudication) and hip area. Like you many miles to a couple of hundred yards before it was painful.
I had mild neuropathy in my feet,
I changed my diet to (very) low carb because I was told (and read) that glucose if inflammatory.
I see you are T1 so honestly don't understand how diet / glucose works with that apart from it being insulin regulated. At least that discussion is one to have with your medical team.
My vascular guy said: No smoking, keep your glucose in good order and exercise.
Those measures have helped me and (touch wood) I've have improved.
I hope you find any underlying cause. Not being able to walk like you used to is very hard to take. I really hope these latest tests put you on the right road.
Best of luck.