I Am The Fattest I'Ve Ever Been

I thought my scale stopped at 425 pounds (that’s what the box said anyways). It actually stopped around 410 I think. I last weighed myself at 406 pounds, but now my scale reads error. I know I’ve gained a lot of weight quickly. My pants and shirts don’t fit. I had to use rubber bands to tie the buttons on my pants together and layer a tank top around my waist under a shirt to make sure my belly and waist of my pants stayed covered. I’m more winded going up the stairs than I was in the last few months. And I can feel a change in how my body settles when I sit down. I would approximate my weight at at least 420-425 pounds, but I can’t be sure. Any ideas on how to get a more accurate weight before my new scale comes in?