I think the confusing wordless sense you have reflects the reality of a child's perception. When trauma happens to us before we have the cognitive and verbal capacity to understand it, it produces emotions that are global and indescribable. One way that therapy can be healing is through the very process of engaging in order to give voice to that indescribable mass of feelings. I think that very much is the challenge of therapy. But it's not simply your struggle alone; the process of trying on different ways of expression and negotiating their meaning with another person both builds the relationship and clarifies your experience. I think your belief that you need to somehow build an explicit case in order for your T to believe you is understandable--it's the fear and maybe a reflection of past experience--but it isn't accurrate. Most approaches in psych concern themselves with the client's reality and the thinking and feeling it creates--not with any objective "truth" of that reality. But clients often unconsciously focus on the objective truth as a way of protecting themselves from painful feelings.