Sibling issues

I have 1 sister, she is married. I have recently found out that over the past 2 years, everything I have been telling her... she has been telling her husband and her husbands mum. Her husband and mum have been annoying with me over the past 2 years about comments that I have made about them in private conservations to my sister. The trust is completely gone, I don't know her anymore. My mum passed away 2 years ago... this was around the same time that my sister got married. Since then i have noticed major changes in my sister. What she has done is not something i can move passed. I keep thinking about it. Was i wrong to trust my sister?