My Wife And I Have Been Battling To Save Our

My wife and I have been battling to save our marriage for three years but we have now separated for three months. she is absolutely convinced that I am cheating on her and became verbally abusive on nearly a daily basis. When I left to get away - she was convinced I left to be with someone else. So, I endured for almost three years but could finally take no more. She also believes that I have stolen money and own other properties (to have my affairs). None of this is true. I am nearly 60 years old, have prostate cancer, and have difficulty with sex. It is all so absurd but completely frustrating. I've not been able to find any help -- but frankly doubt she would agree to seek help. Is there any help? We've been married 34 years - and I'm too old to start over.