is my boyfriend bipolar

What should I do when I feel like my boyfriend is bipolar?
It gets so angry with me and cried out like 5 minutes later, it's all love DVY.i do not understand. i cannot take it. I wish there to stop him because I'm afraid of how he will react!
What qualifications do you have for the diagnosis as being bipolar. I think they are the problem. Also, do not break "brake" instead use ".
Little man syndrome