Hello, Quite often, almost every month, for a few days, i feel lost, lost the purpose for life, feel like screaming and running away from everything, feel very low, uninterested in everything, feel at timese even suicidal but then i keep convincing myself thinkig about my commitments in life, but i dont see any other reason for y i should exist. But this gradually evades slowly after a few days and i feel ok and then after a few days the feeling is back. Should i be worried? This is happening with me for a few years now. Please help. Thanks