I have my moments when i sad and suicidal and hate myself for no reason, but yet i'd be happy and on top of the world later, is this possible bi polar?

Bipolar?: Bipolar is diagnosed following thorough assessment by a mental health professional & after thorough exam by family doctor to rule out medical causes for mood cycling.

Marked mood swings: There isn't a way to diagnose with the available information. However, elation alternating with depressed mood & suicidal ideations can be symptoms of a bipolar disorder. A thorough psychiatric evaluation can determined if these symptoms are due to a mood disorder. Take care.