S.H.
Your Hormones, are still adjusting after having your baby.
PLUS, you have a ton of stress.
PLUS, your Husband does not seem to understand.
PLUS, you do not seem to be getting much help.
PLUS, it seems only you, are doing everything, per the household and ALL the kids.
PLUS, you do NOT get any time off, or time for yourself.
THUS, you are, always on-call. 24/7. Thus no respite for mind or body.
THUS, lack of sleep.
THUS, lack of sleep causes, irritability and mood issues.
So that = how you feel.
And the moods of it.
Did your period return yet?
If so, you may be having PMS.
Sometimes, after having a child, PMS symptoms can be worse. Or more evident.
It is the change of hormones.
If you research "PMS".... you will see that the moods/stress you are experiencing, are the same.