I feel for you. I do. But at the same time, why should anyone else be forced to have a person next to them so large that they cannot fit in their seat?
I do not ride kiddy rides, at the theme park, because I cannot fit.
It is not my fault, or the airlines, or the attendants, or anyone else fault, that your fat. Its your fault. you have over eaten food your whole life, and hence you have an extra X amount of fat on your body.
And the extra cost, is VERY fair. I weight 145lbs. If i want to take an extra 50lbs of luggage beyond what i am allowed, i have to pay more.
If you weigh 245, your already taking on the plane an extra 100lbs. Your fat is your luggage. I feel that plane tickets should in part be based on weight, this is fair to all. If you want to fly, and you weight more, it takes more fuel to get there. You should pay more. no?