Hi Candle, I am sorry you are feeling this way but I can relate as I have always been the 'fixer' in many of what I thought were friendships. What I know now (many years later) is that those who are needy and who are users are attracted to people like you and me. Please don't wait until you are 40 to start to learn to say no. There is nothing selfish about saying it - nothing at all. What I have found is that the true friends I have (who are few) want nothing from me - nothing what so ever - other than company and laughs.
Thinking of you.