Why do i have this feelings? i love my friends as my dad and mam

Im 25 Y.O male,im working as A nurse in one of the general hospitals,i really love my job and my friends, But there is One friend that i love him so much i really care about him so much, his not my age his 47years,ok!!
the story is that we became friens after the head nurse in my department put me in with this friend, i used to see him as an ordinary friend, but when the first time i've been with him i really enjoyed his company, day by day we became a good friends,as he is a senior staff in the hospital and im freshmen still, so i started to learn from him alot,and he always teach everything he knows.
and one day he invited me to his house,and he is married and i like his wife so much also, at first i felt wierd so i apolagized from him that i cant go,and after how many days he invited me again, so i went there,and i really enjoyed their company i had a really nice time.

so after that everytime we finsh our work we go hang out in his place , and one day we started a joke that one day we were in Ikea, we were shoping together, its just me and him and his wife, so because of the age thing it really seems like I'm the son!!!
so i started to call him dad!! it was a joke, its like i was pretending to be their son and they are buying things for me, and i really liked it calling them mamy and daddy!
from that day i never stop calling them that way, Mamy glad, daddy Mike.

and they're really calling me" Son".
even in the work im calling him daddy?

but with time i really think of them so much when im at my home, i miss them ,wondering what they're doing right now?

and one day they quarreled and both of them looked so grumby and crunky when they came to work, and i really felt soo bad!
i felt sad, i used to see them cuddling and kissing each other,huging, and i really feel happy when i see them.
and yesterday,"daddy Mike " was so pissed off,and he was so in a bad mood when he came to work,every time i try to talk to him he would just remin silent, he was so negative, and it really effected me i became so sad and mad because my dad is mad(his only my friend)!!

and then he became so sick, his blood pressure went high, and i was so sad and blue that day.

and today we were so buizy at work and at the end of the duety he quarreled agin with mamy glad, and they left early without even waiting me, because we used to leave out together as a family , i was hurt when i went to the parking and they already gone!
and then i tryed to call daddy,but he is not answering my calls, i really felt warried, and then i started this questions, Why Do I care they are not my reall parents but i care so much about them,and i even felt like im ganna lose them, .
i really dont know my feelings any more, i need help is that normal or there is somthing wrong?

and i really dont want them to be mad at each other i dont like even seeing them sad.
pleas guys just discusse wih me my confussion.