Pete,
I think we all overthink. That is really the main part of this disorder. Our minds have evolved to resolve problems and come up with solutions, answers. The problem with anxiety is this doesn't work. In fact the search for the solution is very much the problem.
Believe me, you will never solve the problem with your mind, but I know how hard it is to stop trying.
Acceptance is not something that is done with the mind. It is convincing the mind to do nothing, to drop the subject. It takes a lot of practice and your mind will object for sure but if the thinking quietens a little then eventually so will the anxiety.
This is the aim of meditation.... Training the mind to focus on the here and now... And every time it drifts off to try and solve the disorder and think about the past or future, usually every few seconds, we practice refocusing on something like our breathing.
Phil