Sadbuttrue, I think everybody goes through this phase, when you feel worthless & you start taking everything negatively. It comes and goes. For me, it is like a cycle, & I am two extremes,sometimes very high, sometimes very low.Being a gal, the PMS thing takes the toll sometimes.Hormones the unknown chems from the designer God.So just be calm, composed and wait for the time. The positive thoughts will slowly overcome your negative ones , & you will feel happy again .We all are with you in this phase.At least am alway there, friend.I know how it feels.You are simply not alone.Actually, I am also suffering the same rite now.