I don't think we can control our emotions to any great degree, although we can take positive steps to maximise our ability to feel better.

Coping with emotions I interpret as more 'living' with them as they are rather than changing them. So for example you feel sad, so acknowledging that, taking steps to minimise the sadness, whatever that may be in your life, but accepting that you feel this way now.

Are you certain this is post depression? Those symptoms, waking up feeling sad, feeling sad much of the time, sounds like it could be depression to me, maybe just a different phase.

Hope you will find a happier equilibrium in time