Living with a paranoid parent, I can't take it anymore....?

My moms been paranoid since I've been ten, everyones a secret agent, everyones watching her, everyone wants to hurt her, I dont think I can tolerate it anymore, 11 years is too long, I'm drained by noon every single day from trying to reason with her and answer all her questions. Moving away from home to study just made it worse, 3-4 calls a day. A month ago she asked me for weightloss pills, got them for her, she didnt lose any weight on them cos she didnt diet or anything, so she was convinced I made aspirin in University and switched out the pills. Just tip of the iceberg. I can't take this anymore, I can't, and shes not willing to get treatment, but how many paranoid patients are actually willing?? What can I do??