I think I have Bipolar Disorder for 4 years and just realize it now. What should I do?

For 4 years I have this extreme mood swings. At first, I thought people surround me are just being a jerk which makes me depressed. But, sometimes I feel so happy and full of energy. This makes me really awful and unproductive.

That makes me questioning about my life, do I have a sad life or a happy life? And then I stumble upon an article about this depression type.

So, do I need to go to psychiatrist? Since I think it gotten worse these day with stress from college and some family issue. Or is there something I can do myself to cure this mental illness?

I really want to live as a normal person and not dwelling in my sadness.