YF : Why does my husband act like that?- He has no read my manual (LOL)

Hi Brooke,
This work is awesome and eye opening, bu at the same time its soo hard!!! to realize that its how i think about it , or what i think about a situation what drives me crazy or makes me angry… lets evaluate the following:
C: my husband is watching our baby girl for the day ( she is 1 yr old)
T: He is not feeding her on time, or not enough, or he gets distracted and forget to feeds her
f: angry and full of worry
A: get upset and tell him he is not feeding her enough
R: we both get angry at each other

after listening to one of your podcasts , where you said that if the phrases in my mind are: he should act like that and other phrases similar, those are just my thoughts and they are optional, OK i totally understand it intellectually or the concept but I dont seem to be able to apply it to my life to change how i think, feel and act.. please help. What intentional model should i have?
in the example above the results or the truth are: My daughter is well nourish and she seems to enjoy playing and being with her Dad, but then why i keep thinking she is going to be in danger when she is not with me and left with Daddy?
I’m so frustrated!! please i need help