I personally think that it is much better to inform people when your mood is bad and you need to be left alone for a while or for that entire day, than to unleash your anger at unsuspecting people, who maybe your friends, colleagues, relatives, associates, spouse, siblings, partner/s, mates or family.
Be the discipline you expect from others, yourself first.
To further expand this philosophy, I also think that it is completely and perfectly okay to not receive anyone's call under this situation and/or even give any explanation for not picking up.
Don't talk until your mood becomes right again.
And if you can trust the person in question to make you feel any better by talking to him/her, then by all means, you should go ahead and take their calls, even when you are down!
Hold no hatred or ill feelings towards anyone: they gave you what they could give you.
You can either warn them or leave them. But anger does you no good.
If your intentions towards all living things are good, i.e. if you are not here to harm anybody, or any living things, then I guess you don't need any religion.
Cause' that is basically, the ultimate goal of all religions and if you have already achieved that goal, then why would you need a religion?
Time to think!