couple of months ago, about 3, my mum brought back a male japanese spitz that her friend had given up on due to economic reasons. initially, he adjusted well into our household and i liked him. however, since last mth, he has began to bark at me whenever he sees me( that includes me coming out of my room to go to the bathroom. he is very protective of my younger sister and brother. what could had triggered these behavior? (i understand spitz are a kind ofguard breeds though). he just continues barking n barking and now my whole family is dreaded of this.
i noticed the only time he doesnt bark at me is when i'm eating and he would come infront of me looking at the food. it gets me angry sometimes that he's always barking at me yet expects me to give him that juicy chicken

is there anyway i can exploit this point to change his behavior towards me?
PS i've included his photo