I'm my elderly mom's primary caretaker and was recently diagnosed with ovarian cancer. My sister was helping a little, but now she's pulling out even though she knows about my health. What can I do?

I'm so sorry you are going through such a difficult time right now, Annabelle, and that you have this dreadful diagnosis & no help from your siblings. I think it's a really good idea for you to sit down with a Certified Elder Care Attorney who can help guide you through your options now. Someone who knows the Medicaid system and whether or not mom AND you qualify for benefits; her for long term care, and you for health care benefits. He may also be able to advise you about selling mom's house which is out of the area; things like that CAN be done with a real estate agent's help. Or he may be able to guide you about getting a home equity loan to finance care for you and for mom both, at least for the short term to give you some respite.

I very much hope you can find a way to deal with everything you have on your plate. Sending you a big hug and a prayer for courage and strength at this difficult time.

Me and my mom are not living in her home but we are living in my home in another state. Sorry, I should have said that. I am having a hard time even getting through all the forms that needs to be filled out for her even though I am doing it all anyway. I just don't have anything left in me. We are both just stranded here with no one to help us.

No one should have a harsh answer for you because you're going through a lot.
About your mom's house and Medicaid though. The rules for it are different for being at home on Medicaid or using it to pay for care facility placement.
Medicaid is based on whether or not people are low enough income. If you have no income or low enough income you will meet Medicaid requirements and may even be able to get some home/health services for yourself.
My mother is on Medicare and Medicaid. Medicaid is a federal program, so if she and you meet the federal requirements for it, you can get it. She owns a house and lives in it. So do I. She and you will qualify for homecare services that will cost nothing up front, out-of-pocket for either of you. What happens with Medicaid is that those services will have to be paid back after the person passes away if they have assets. Your mother has the asset of her house. After she passes away, that will have to be sold to pay back any Medicaid-paid homecare services she may receive. Unless it's been taken out of her name or put into an Irrevocable Trust longer than the 5-year look back period Medicaid does on finances.
Medicaid is not unreasonable and from what you're saying here, you certainly are a hardship case. They take that into consideration. People often make the mistake in thinking that Medicaid is this greedy and merciless entity that will stop at nothing to take everything a sick or elderly person has. Not true. That's how the business end of nursing homes, assisted livings, and memory care facilities operate. The two are not the same thing. Your mother's home may very well be an exempt asset because you're a hardship and live there.
InFamilyService makes an excellent point lower on the thread. Your doctor can set you up with a social worker who can help you with all of this. I'll be honest with you. I've had good experiences dealing with social workers and bad ones. It would be worth it for you to be in touch with one though. Please ask your doctor about it, and keep us posted.

The house is an exempt asset. Mom could go to a nice NH and you could stay in the home since you were her Caretaker. Or, you get "in home" care for Mom. This means Mediicaid will supply an aide. You need to contact your County Social Services office and speak to a Medicaid caseworker. Maybe both you and Mom can get in home care.

My apologies vegaslady. OP should contact Seattle U School of Law or UofW School of Law.

Your primary care doctor has a social worker that should be able to help sort through some of this.

It is obvious your siblings are not interested in helping either of you.

I feel so bad for you being alone with all this. You need to take care of yourself.
Think about contacting your church, friends, cousins, anyone that may help sort through some arrangements.

Mom may qualify for medicaid anyway and maybe you too. I do not know your age.
Where do you both live now?

OP is in Seattle per the profile. What I posted earlier is relevant in WA

Apply for Medicaid and let them determine the house issue. Seriously, the house may not be the problem you believe it to be. It is only my humble opinion, but it sounds like she might actually get Medicaid and when she passes, the house goes through estate recovery and that is that.

There are also several legal NPO's in Nevada that help with these things. This is not an endorsement...Southern Nevada Senior Law Program — Helping Seniors Understand Their Legal Rights in Southern Nevada (snslp.org)... just something I found with a quick search. They may be able to give you more options and help so that takes some stress off of you.

Have you actually looked into MedicAid for Mom? Even if she owns this other property she may still be eligible if she is making a legitimate attempt to sell at a fair market price. There are rules that deal with this but it comes up so infrequently that most people, including case workers, aren't familiar with it. There doesn't need to be that much involved in the sale if you can locate a realtor and sell it as is.