Depending on your age and disability, you may be eligible for government supports. It won't be a lot but might help to get you out. Any family you can live with? You can't stay and be treated so poorly. Remember too, in a divorce, you will get some assets and maybe alimony depending on how long you've been married. Please consult an attorney. Also 211 can tell you what services you are eligible for. Starting with a therapist might help. 

NOTHING!!

Your SD and H are both treating you terribly. Unless your H chooses to step up, address the issues with his child and him actually treat you with respect as his wife, what else can you do. 

Is your H open to counseling? Does he understand that living this way could be a deal breaker for you?

Maybe bluntly telling him that blame for your failing health due to the stress and the possible end to your marriage lies squarely on his shoulders. What does he say to that?

Does he accept any responsibility in this? Does he have any solutions or ways to resolve this? Or just wants to carry on with the crap?

If hes unwilling to address the issues and make you a priority then only 2 choices...

Stay and put up with it

or leave.

It sounds like your H doesn't want to deal with this and expects you to tolerate her crap. Icing on the cake is that he wants to make you feel bad for not wanting that life.

A marriage is 2 people. Unfortunately too many spouses look at it like its them and their doormat. I was done being the doormat and had to get out. 

I had not worked in 2 years. Had no money but plenty of debt. Family helped me to get out. 

Do you have anyone who can help? Someone you could stay with for awhile so you can leave?

Maybe even a break for you? Go stay with someone for a week or two. Get some rest, clear your head and let H deal with SD and day to day life on his own for a bit.

Good luck to you. Take care!!

How old is this woman that your duh is scared that something might happen to her? Does she have some kind of disability? 

They will let you know what options you have. If you are unable to work due to disability, you may qualify for lifetime spousal maintenance. 

Your husband has made it clear which relationship he is going to fight for, and it isn't your marriage. Time to seek legal counsel. 

Find out what disability income you can recieve. You must get away from this abuse. 

Your SD is a spoiled B. Your DH is worse. He showed you where you stand. As much as this hurts, and it does!, remember its not you. Your DH has a sickness. He puts his SD above you, like she is the wife. Its creepy, sick, dysfunctional. That is why you are physically ill. Its abuse towards you.

HUN please find a place to go. This will never change. Your health and well being is top priority, and since your DH does not place you first YOU have to.

Wow, I am sorry you are dealing with this. Jeez how old is this woman? I can't imagine wanting to live with your parents your whole life. It's gross that he allows his kid to be a giant loser. I think you should try to seek legal counsel to see what you are entitled through in a divorce. The way he is treating you is gross and you should not be put second to a failure to launch.

My FIL is stuck in the same situation. He is still supporting his 38 year old SD. She just never moved on with life. He desperately tries to solicit the guys he works with in hopes of pawning her off on one of them. She spent 12 years getting her bachelor's degree in special education and just graduated in 2019. She landed her "dream job" and after 4 weeks she said she didn't like working with kids and quit. He paid for her entire 12 years of college and gives her money weekly. His wife left him twice because he didn't want to buy his SD a new BMW. He gave in just to get her back and every 2 years she gets a new luxury car. He is absolutely miserable and has become an alcoholic. It's really sad and I hope he finds the strength to kick her to the curb one day. It has really destroyed him as a person over the years. You don't want to stay and be abused by these people. Take care of your health and wellbeing.