Many people with high-functioning autism or Aspergers Syndrome have been previously misdiagnosed with ADD, bipolar or OCD as they share some symptoms. I have Aspergers Syndrome, but had been misdiagnosed several times before. I’m not a mental health professional, so I don’t know if it’s possible to actually have more than one of these conditions.
As an adult diagnosed with AS, there is not much that can be done about it. The only treatments (there is no cure) are aimed at children and adolescents. An adult can make progress, but it’s very slow and frustrating.
I recommend that you get evaluated and diagnosed, since bipolar disorder is highly treatable. Even with a diagnosis of an autism spectrum disorder, you would at least have the peace of mind from knowing what it is.
Sometimes just knowing the characteristics of AS can help you conciously avoid displaying certain of the associated traits. For example, I now avoid discussing topics that I’m interested in F2F unless I know for certain that the other person is interested.