I feel depressed and suicidal for a few hours then great and talkative the next few hours. what is wrong with me?

Rapid mood changes: You can't be diagnosed via the internet. But suicidal thoughts are very concerning. If you have a suicide plan that you have the urge to carry out, please be seen at the nearest emergency room asap. You can be driven by a friend or relative or call 911 for help from emergency services. If less imminent, it is very important that you tell your physican. He or she can evaluate for medical / >>>.