exact, matching, identical, alike, duplicate, twin; indistinguishable, interchangeable, corresponding, equivalent, parallel, like, comparable, similar, congruent, concordant, consonant.
A synonym.
enraged, livid
ardor, passion, craze, love. Some other words with similar meanings to the word obsession are: fixation compulsion fetish infatuation neurosis fascination mania addiction fixed idea dependence...
frequently....recurring