unmanageable
un-man-age-a-ble
adjective
Too difficult or impossible to control, deal with, or direct effectively.
"The workload became unmanageable for the small team."
Thesaurus
Synonyms: uncontrollable, indocile, unruly, uncheckable, ungovernable, incorrigible, difficult, uncorrectable, intractable, bunglesome, awkward, unwieldy
Antonyms: manageable, wieldy