That sounds a little like my mom when she is very drunk. Especially after her brother died, she was even more of a mess for awhile. She left a burrito in the microwave once for 30 minutes. The whole house filled with smoke. She's left the stove and oven on.
She's a little better now though. After I moved out, I guess it was a little wakeup call of how she was affecting other people, although she still drinks, but not as much.
I think the strokes have obviously damaged your mom's brain though. I feel sad for you that this has fallen upon you to deal with, and that you have no other family. Same here, no family. You're the strongest one out of anyone you know, I'm sure. You might have to use that strenghth to make a difficult decision.
I think some of the other posters have a good suggestion. Talk to someone in social services. Your mom's brain is not normal. She needs that help. So do you. This is doing damage to you too. She may not truly mean what she says to you, but it still really affects you to hear things like that from your own mother. I don't live with my mom anymore, but when she is drunk and tells me things like, "Everything you touch, you destroy! Get out of my life!" (when I'm trying to help her) I end up feeling so hopeless about everything, and a part of me believes her. It's hard not to let those comments eat away at you. Especially for you, you are constantly in that environment, and can't escape. It must be torture to you. I think if you mention to a social worker that she has threatened to kill herself, or even you, they would take notice. I don't have a lot of experience with that, so maybe someone else can tell you what the process is like. Who knows, maybe there is a temporary care and treatment option. Anyway, to deal with the vicious comments, and tone, you could use earplugs for now. Just to help keep you sane until you figure out what to do. At walmart, I purchased the silicone ones. You can still hear stuff, but it's pretty muffled. I thought it helped to not hear the abusive comments.