Thanks to everyone who replied!
I called today and well, within 30 seconds of trying to explain what I needed help with, I burst into tears. It was the part where I had to explain my change in circumstances. The lady who answered the call was lovely! She calmed me down, was really patient listening and said it would be okay.
So, she put me back on the register and tomorrow I can call the office and arrange a course, asap. Cross fingers I can book one over the next two weeks!
I think I was lucky - I hadn't deliberately ignored it and I have not yet received a summons or anything - it was obvious I genuinely wanted to do the speed awareness course but had misread the letter. She was just lovely and said 'Trust me, you will get through it!' which I think was a reference to cheating men :o)
Cross fingers now I will get to complete the course in the next two weeks
x