I have an anxiety disorder, and I managed to get through a very stressful few weeks (work deadline, family difficulties, a minor injury, a moth infestation and a difficult accountancy exam), without my anxiety causing too much trouble. A couple of weeks ago I felt paralysed with anxiety, and I forced myself to have a rest and to do some mindfulness exercises. I did the same the next day and I started to feel less anxious gradually. I completed the work deadlines and I'm pretty sure I passed the exam as well.

EDIT: This is particularly significant, since my anxiety has certainly improved a lot over the last couple of years. However, I was worried that it would become severe again in a stressful situation. I'm glad that it hasn't!