Can I cancel my appeal at the last minute

Hi , sorry I haven’t posted i.a while . I am due to go to my appeal tomorrow but cannot face it . I did get awarded the care component and low mobility, but had to return my car . I have been told I was lucky to get anything and they can overturn that decision at appeal. What will happen if I write to the judge and explain that I don’t want to appeal. I am worried I can get into trouble for wasting the Judges time . Would I be better sending in a letter explaining why I can’t face it and pointing out what I thought was wrong in my assessment. Thank you