How to break free?

I feel like I am on the crazy roller coaster cycle. I am doing good, confident, and managing to not only keep it together but also acomplish things. Then out of no where I feel like I not only ran into a brick wall but that I am also trying to climb over it and maybe even hitting my head on it a few times as well... Anyways, i am sick of this cycle but I dont know how to break free or to not care. Words hurt and actions are telling of the hearts true intentions. I want to have my act together all the time and I want to manage it all and not have these breakdowns. I hate the weak feeling it leaves me with. Am I supposed to learn something from being weak? I want to be positive and uplifting and encouraging and I feel like I fail at that most of the time. Is it a matter of the mind or the heart or both???? How do I change this cycle???