C.O.
the knots in your stomach are stress brought on my guilt. Guilt because when in an argument people say things to hurt the other instead of stating what the problem is.
Put the argument out of your head. If you can't talk or communicate with the person - then you really can't have a relationship with them, can you? So if that is not an option - stop.
Stop giving them free rent in your head.
Stop giving them an option in your life.
Stop giving them credit in your life. If they cared about you like you cared about them - then talking and resolving would be an option.
Things that MIGHT help get you out of a funk?
Go walk around the block.
Go work out.
Go write out your feelings in a journal.
Go write a letter to the person and don't send it.
Go type an e-mail to the person and don't send it.