Help advice!

dravstvuyte !
Please help me advice!
It is necessary to call the man first?
Separated for over a month ago. On his initiative. Miss him very much … See each other from time to time ( operate in the same building ). He first begins to talk. I do not want to run after him, but without it I feel bad … Maybe he does not know what I feel for him …
Prompt is to write him a call?May ask for mercy. When he said that we part , I slapped him across the face , no law was , I know …
What should I do ? Going crazy !!!!!