you sound pretty depressed , for good reason it seems. It also seems that you are logical ,and know what you have done wrong.
If you are in Ca. you would qualify for medi-cal that would cover the surgery , but the weight is just one issue.
I have an adult daughter who will be "on the street" next month ( she has no plans), if her x of 15 a year marriage won't help her. She also has made some real stupid decisions , and she is going to have to live with them.
If you want something different than what you have, CHANGE what you are doing.
If you want a job , go everywhere to get one , WalMart, McDonalds, piza delivery..ANYTHING , it may not be enough to live on BUT IT IS A START , I have given the same advice to my daughter , yet she sits at home in front of the T.V. , doing nothing, thus proving to us all that she really doesn't want to change
She has proven by her actions that she will not help herself , and you and she will find that others get tired of being used and soon won't care or will only be willing to help you as long as you are trying to do SOMETHING to help yourself.
Somehow you need to see a doc , get some counseling and get any
job you can.
I really do feel for you because it sounds like you are in a really bad spot , you need more help than a forum can give you.
I wish you all the best , you need to start making better decisions, but you already know that
Best wishes !!!