It's not just my step sister's hoarding issue that makes us wonder about how long her new relationship with her boyfriend will last, there are other reasons.

I have two step sisters who are hoarders like me, only I'm trying to do something about it. At least I only have a cat to deal with though, they have kids, my niece and nephews, living with them. Only brightside is one of them started dating a guy with the need-to-stay-clean type of OCD and was in the army, so my nephews who are her sons are learning how to keep their area clean, but it's also makes everyone curious on how long this relationship will last

You need to find your own place to live that is not at your mother's. You will not be able to help her with your sister also hoarding as your mother will play her love for your sister against you to maintain her hoard.
You need to realize that by being the financial provider of the house, you are in financial control of the hoard and that your money is enabling the situation. You have been in a co-dependent situation with regards to your mother and cannot help her until you detach from that co-dependency.

Please get some counseling for yourself. You have sacrificed enough.

Hi Heidi,

I'm a recovering hoarder. The bad news is that you cannot change a hoarder's behavior until the hoarder wants to change. Also, by the time a person is at their "wits end" they are usually not emotionally and rationally in a place where they can really help the hoarder. Because things that are the opposite of helpful: yelling, threatening, shaming, taking matters into your own hands... Are the natural response to the feelings of anger and fristration overwhelming the non-hoarder.

What the hoarder needs are huge helpings of patience, understanding, and encouragement. That is one thing that is helpful about an online community like this, there is often someone who can sincerely praise you for throwing out a pizza box. Which genuinely helps.

I think in your place, I would focus on the home I was living in. Does your sister ever come over? What is your mother hoarding? How hoarded is the space (can you see the floor? How much floor? Is it possible to safely cook?)

Is the hoard growing, and if so,what is the source of the addition material - how is it coming into the house?

Understanding why your mom hoards is an important first step because different motivations for hoarding can have different solutions. Is it possible for you to have a non-judgemental conversation with her about why she is keeping things? Do you think she would be able to be honest with you? It can't be a confrontational "Why are you keeping this (subtext "garbage")?!" It needs to be a genuine question. "So, can you help me understand why you are keeping these magazines? What is it about them that is important to you?" (Subtext, I'm willing accept your values as valid - you don't have to buy into them, just understand what her values are.)