Feeling betrayed, how do I handle it?

A few weeks ago an acquaintance sent me.a series of angry texts. While working through what seemed to be a misunderstanding I learned that my best friend shared with her personal things I confided with him. For months they had been discussing me and at least once spoke poorly about me in front of other friends. I reached out to my best friend; he apologized, and we talked through it. I felt our friendship was worth fighting for but am struggling to move forward. Since then we still text daily and have gotten together twice, but it feels different, uneasy. And I cannot bring myself to be with both of them together, and they are now together a lot. Where do I go from here? Am I making too much of it?