trust issues

It doesn't matter how many times someone reassures you of The Truth - if you don't trust them you simply won't believe them. I had a poem in my diary as a kid that went something like "friendship is like a china cup, often both beautiful and rare; but if broken, though well-mended, there's always a crack there" - it's a bad rhyme scheme and china cups aren't all that rare, but the sentiment is bang on. I would be an idiot to believe someone who has played me for a fool before. But how to be friends with someone you wouldn't trust as far as you can throw? How to stop hanging out with someone whose been around for-like-ever? How to reconcile your desire for their easy companionship with your self-preservation instincts? Giving advice is easy: walk the fuck away. Taking advice is a whole other story. I am thoroughly disgusted with myself.