suggestion - go to an ear/nose/throat doctor - - - you may have a vestibular problem - Causes of Dizziness | Vestibular Disorders Association
you know - (i'm sure you know) - any med can cause weird reactions in people - and every person is different. the meds surely list their adverse reaction, but statistically, not all. your inner ear may have been damaged from one of your meds - & until you find out if that is true you won't know.
concentration is another matter - but hopefully, maybe - if an inner ear/vestibular problem is causing your problems - fixing that may help your concentration.
i wish you well.