It sounds like you have pretty severe anxiety with some obsessive thought patterns mixed in (this is not uncommon for people with anxiety). Have you ever seen a therapist? Any good therapist could help you manage your anxiety better so that it doesn't negatively impact your life as much as it is currently. There are medications that can help too, which you may decide are necessary, but even without medication, therapy could prove useful in teaching you coping skills, helping you counter-act your negative and/or irrational thoughts, and ultimately helping you stop obsessing.
You might be interested in doing some research on obsessive thoughts (this is sometimes called "Pure O" for the purely obsessional form of obsessive-compulsive disorder). It might help you to read about this kind of thing as you are certainly not alone in struggling with anxiety and obsessive thoughts.
Given what you have said here, I do not see any evidence of your having bipolar disorder.