Procrastination is not a symptom of lupus or uctd. However, depression is common and procrastination is part of not wanting or being able to face even small tasks and challenges. Or just not wanting to find out anything else bad. I had the same problems but tried to focus all my energy on getting better and making appointments, etc, was part of that effort even though I feared each one would, and often did, find something else wrong with me.
It might help to start making a daily to do list and prioritize your tasks. Do the most important one first so if you run out of energy or motivation at least you have accomplished the most important tasks.
Just a suggestion.
Hope you feel better. Being sick sucks but I try to think about getting better and also enjoying each day.