I don't have any answers here as I'm working through a very similar situation, but I wanted to share that so much of what you've written resonates with me, and you are not alone. For a long time my frequent handwashing didn't get in the way of my life, but recently it's become very bothersome. It frustrates me and I want to get rid of it quickly and completely. I wash my hands several times each hour, and have to redo the process if my hands bump into anything, making it take much longer than it should. I also have to open some cabinets and drawers with a napkin. Finally, the people closest to me are noticing, and being bothered by, my obsession. My relationships are being strained and could possibly be broken if I don't fix this soon.

I'll note that as I've delved deeper into therapy, my obsessions on the whole have eased, and since I've been taking medication I feel I've been doing better overall. So those things worked for me, but I know that the cost, time, and energy can be prohibitive. I'll just give you a gentle nudge to reconsider though and try to look into free or low cost options that might be around you...you may be surprised by what you find.

Other than medication and therapy, I've found mindfulness meditation has quieted the obsessive force a bit and am hoping it will continue to help as I'm trying to get better. Doing brain games like those on Luminosity puts me in a certain mindset that also seems to chase away the obsessions. I'm hoping doing more of this will continue to get my brain back in shape.

As far as your mom goes I think that it may not be helpful to go over who's more to blame, but knowing that you can only change and improve yourself can be comforting. Would it be helpful at all to choose one or two things to try to address them and sit down with your mom to discuss this? She may be feeling overwhelmed by it just like you are, and just doesn't know how to support you. Perhaps if she knows what you want to try about this, then she'll be able to step back and give you back control.