Could I have Bipolar Disorder?

Since about the age of 13 I have been feeling out of sorts, I have bouts of intense paranoia (example: walking through town and thinking everybody is staring at me, so Im constantly looking around at people, this gives me headaches so I tend not to go out if I can help it) I sometimes get a bit over excited, constantly have many thoughts in my head but cant make head and tail of them and I tend to feel guilty alot and think that everything is my fault, I have also attempted suicide twice. This is affecting my homelife but I feel like my doctor may fob me off if I go see her. I have been checked for diabetes twice, but tests have come back as clear. My aunty commited suicide due to bipolar and my father was diagnosed 4 years ago. Is bipolar hereditary?? Or could things in life trigger somebody to develop bipolar??? Thank you for reading and thank you for you answers....