What should i do if a guy is indifferent toward me?

i and he work at same place, he was very friendly. He was always smile and hug me every time he see me..but he only did it with me, not others girls work there .We usually took break at same time and talking to each other, he also told me that he love me sometime.Sometime I hug him back and joking around with him...but suddenly,one day he became so quiet,he did not smile or look at me like before and just normal say hi to me...i feel that he is indifferent toward me now....what should i do now?...should i stop talking and stop go break at same time with him...do need to avoid him too???