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The problem you are having is called an Arterio-venous malformation or an AVM more popularly which is an abnormal collection of communicating vessels which are shortcircuited.
Due to abnormaly fast and high rate of flow you hear the swoosh.
Probably the AVM is pressing the auditory pathway to affect the hearing.
The low TSH
seems to be a de novo problem and I do not see a link between the two.
I hope the advise would be helpful for you.