If friends disappoint you over and over, that's in large part your own fault. Once someone has shown a tendency to be self-centered, you need to recognize that and take care of yourself; people aren't going to change simply because you want them to.
When the only bond between close friends is attachment, then even a minor issue may cause one's projections to change. As soon as our projections change, the attachment disappears, because that attachment was based solely on projection and expectation. It is possible to have compassion without attachment, and similarly, to have anger without hatred.
Then, though I prize my friends, I cannot afford to talk with them and study their visions, lest I lose my own. It would indeed give me a certain household joy to quit this lofty seeking, this spiritual astronomy, or search of stars, and come down to warm sympathies with you; but then I know well I shall mourn always the vanishing of my mighty gods.
He that wrongs a friend Wrongs himself more, and ever bears about A silent court of justice in his breast, Himself the judge and jury, and himself The prisoner at the bar ever condemned.