Here's an example of how I practiced when I was emotionally upset:

Let’s suppose my practice outings consisted of driving 5 miles from home.  And let’s suppose I had repeated my 5-mile outing several times, and now my anxiety level was down to a 1 or a 2 – I had really mastered the 5-mile outing.

On my next outing, I drive 6 miles, and I'm at a 4.  So far, so good.  But the next day, something happens to get me very emotionally upset, and I don't feel like practicing at all.  What should I do?  

Here’s the answer:  That morning, I give myself permission to repeat the 5-mile outing.  In distance, I'm going back a step, but I'm adding "while feeling upset," so it's still a challenge.  And, I'm continuing to practice!

Let's suppose I’m upset for 2 or 3 days.  So, I repeat that 5-mile outing.  After 2 or 3 days, I'm doing "5 miles while upset" at a 2!   That's a great practice.  I've really extended my range, because now I can go 5 miles while upset, with low anxiety!