pip online appeal

Hi I know I have asked this question before but I'm so worried . I got a letter on the 2nd April telling me that the mandatory reconsideration has been turned down  . the letter was dated the 18th march but I did not receive  it till 2nd April  we have started an appeal online but we have had a lot of problems in our family with deaths and illness plus my mental heath is through the roof its supposed to be submitted by the 18th of April but because of the delay in the post and other problems it may be a bit late but I'm worried that they wont accept it please any advice  would be great thanks.