Synthroid can cause all
the symptoms you mention (except, to my knowledge,
the vision problems). However, most
of those symptoms could also be the result of undermedication of Synthroid (i.e. you are still hypo and need a Synthroid increase or change to other meds).
Atenolol slows your HR and lowers your BP, so that is not likely the cause of your tachy, in fact, it should be helping to control it.