PIP - Appeal, missed the deadline, Advice needed

I have been having a rough ride with life in general over past couple of months.

Have been going through my letters, and have read again the letter resulting from an appeal of my personal independance payment.

I read through the letter, and have found a sentence which stated something I said at the assesment interview, but I didn't say what is written down.

I also realise that I only have one month to appeal, but that deadline passed 5 days ago

Not sure what to do, they state I must let them know if my condition changes in any way, but it doesn't match what I told them.

Not sure what I should do