Welcome! You don't need me to tell you that subsisting for months on water, coffee, and occasional celery and carrot sticks is probably not a healthy way to lose weight, so I won't. 70 pounds in 3 months is still a huge loss in a short amount of time, even with those eating habits. You were definitely the anomaly.
Everyone loses at different rates, depending on age, genetics, plan, etc. I do not lose at nearly the rate you have described, but I lose faster than other people. The way that I get through the early months of weight loss, when scale losses don't seem to be showing up in size losses just yet, is to focus on the positive parts of taking care of myself. I feel better when I am eating better and exercising, both physically and mentally. I learn about myself, and I get stronger and more capable of doing physical things.
It's a long road to a 100-pound loss. Glad to have you here as a fellow traveler on this difficult path. Good luck finding your zen with the difficult early parts, and good luck finding the answers to your medical issues.
onederland in 2016