I can't say whether this is true for you or not, but in my life I have found how often my friendships play out my old traumatic family relationships. I end up in relationships where I feel squashed, invisible, 'less than' with other folks who seem powerful, vent their frustrations on me, and are happy to take any help I offer but don't help me in return.

It's very challenging to break these old patterns, to, as Veiled said, not be a doormat. I know I have a hard time trusting what I think--I ask myself, what if this person isn't harming me and I'm overreacting? But any relationship that hurts you more than helps you, or where you fear a friend's wrath, is not healthy.