Hi there ~
It is not uncommon to have these symptoms of feeling low, having difficulties with concentration, easily forgetting things, feeling tired and lethargic, becoming emotional and hopeless in cases of depression
. You may be able to attribute it to situational factors. I recommend that you consult a qualified psychiatrist
to get on medications, SSRIs to help with mood elevation. Also, doing things that have traditionally given you pleasure might be one way to go. I hope this helps.
Take care and have a nice day !