What's going on

Hi everyone so iv gone from usual 28day cycle to then having a 56day and now 20day. So I'm 8 days early this month and my god it's bad! I came on yesterday and iv come on that heavy iv had to use 2 night pads at a time and changing every 20 mins. And the pain is unbearable. I'm usually really good with pain as I have a high pain threshold but today I'm in tears. I honestly cant cope dont know why this could be. Please any advice would be very much appreciated I cant cope no more