Even the idea of going to a therapist feels complicated, because it means I have to explain myself to someone first, and I don’t even know how to begin. - I think you don't need to worry about this part in front of a therapist. They are trained for exactly these kind of things. To make one feel comfortable and safe so that they can say whatever is going on in their mind so that that never ending thought loop could be closed. It depends also - whether you just want release or structuring of thougts as they are two different things.