Kyle, you should not feel bad about questoning your sister about what was going on with her in Paris. You have lived on the other side of her addiction for years and she has violated your tust many times. Kim needs to own that and show you more understanding. She is the addict and she needs to earn your trust back. She needs to realize that it does not come automatically. She did not act right in Paris and you were not wrong to question her behavior.
I know what it is like to live on that side of addiction and it isn't easy. You did nothing wrong.