I can't understand my son is crying all the time I stopped reacting, h…

I can't understand my son is crying all the time I stopped reacting, he cries, I lie next to him and he calms down and then again We might turn over in our sleep and suddenly sit and cry and then back he lies and falls asleep I don't know what to do anymore I'm getting nervous already I leave for another room and he starts crying and runs to me