Hello from JustAnswer.
Sexual promiscuity, including high-risk sexual activity, is a common feature of bipolar disease, and to a lesser extent of cyclothymia. This is actually one of the criteria for making the diagnosis, although it is usually worded differently, such as engaging in risky behavior or excessive pleasurable activities that have significant risk for adverse consequences.
If recreational drugs are also used, that can exacerbate the engaging in sexual activities.
As for whether there is something really wrong with you, there is no reason to think that there is anything wrong with you beyond what is already known - the cyclothymia and recreational drug use.
As for what to do, there are a couple of options. You certainly can consider the use of medicines that may be able to get better control of your symptoms than the recreational use of cocaine. There are a number of mood stabilizers that can help with cyclothymia and bipolar disease. Some of these medicines were first marketed for seizures and later also found to help as mood stabilizers, such as valproic acid, carbamazepine, or lamotrigine. Other medicines are primarily used for mental health conditions, such as lithium, aripiprazole, or rsperidone. It also may be very helpful to consider counseling. Counseling can help you to learn techniques to control intrusive thoughts, behavioral management strategies to reduce risky behaviors, and method for stress reduction that can ease prevent relapsing symptoms.
If I can provide any additional information, please let me know.