You might consider getting a professional diagnosis, and especially being screened for bipolar disorder. Hypersexuality, or, in layman's terms, "a high sex drive," is a symptom of bipolar during manic/hypomanic episodes. Loss of interest in pleasurable activities, like sex, can be a symptom of depression. Having some symptoms is not a diagnosis, nor should you self-diagnose; talk to a professional and get a formal screening for this condition if this behavior is a problem for you.
Bipolar disorder, as well as most other mental health conditions, is treatable.