Because you love them and you want them to love each other and you want them to love you too...it hurts your spirit. .making you sad.... I think its normal.

my mom used to cry when my brothers would fight each other... it broke her heart to see it and she never wantd to be in a position where she had to choose sides either.

AS for when your kid treats you with anger.. it hurts.. I get hurt when my teenager talks to me like i am the worst person on the earth.. but I have to try not to take it personally.. he is finding his own voice... he doesn't hate me ..

its okay hun... try not to worry so much...