Do i have bi polar or not?

I dont know if it could be bi polar or just a teen thing. Basicily i get depressed a lot to the point ive thought about you know what a lot of times, also i never really have a relaxed mood, im either depressed, energetic or angry. And 99 percent of the time the depression starts when i think about a ex girlfriend or a future without love. Could it be just because im a hormonal 17 year old or have a really got a problem?