Bipolar Disorder- Extra Martial Affair

I'm 24 and was involved in a extra martial affair with someone 10 years elder to me. It was all honest from my side and promised to marry once she's done with the divorce. I was ripped off physically, monetarily and mentally and I'm suffering from Bipolar Disorder. I want to to tell everything to her husband because shes made my life hell. She's about to go for divorce and she's a mother to 9 years old girl so there are custody issues. I want to say things to her husband as soon as possible My parents are aware about everything. She's threatened me that if I say things to her husband she will ruin my life. She might kill herself and would blame me I know ethically I want to do is wrong but I've suffered enough now and I can't anymore. Would it be illegal if I say things to her husband? Is there anything I can do in advance so that if in case I tell her husband and later if she creates any drama I won't be blamed? I tried sorting out things nicely but she's got arrogance of her own. Should I consider any measures legally before I inform her husband?