Well, i googled the meaning of the expression: a bad taste in my mouth - a feeling that something is false or unfair, a feeling of ill will I left the meeting with a bad taste in my mouth. There was a lot of dishonesty in the room. So maybe a more meaningful and modern translate is: 让我感到有点不爽。(I am not feeling cool.)

Perhaps…How about this? ……让我心里很不是滋味儿。

在我嘴里留下了苦涩的味道

“……在我的嘴里留下苦涩的味道”。