got problems getting my dog to eat

my dogs from a shelter, i got him in november. he ate really well for the first month maybe a bit more. i noticed hes like scared of the food bowl, its a stainless steel one, so i switched to a ceramic one still scared, i switched to wax paper....still scared. hes scared if im moving it, when it stops moving he comes to it but just sniffs it and than sits and doesnt want to eat. i have to almost bribe him to eat. ive tried dif dog foods, even canned. i did a dry/ can mix meal and that worked for a good couple months. now its straight cans and he still doesnt really want it i have to hand feed it. and than i switched to cooked food (chicken beef prok) ate it for a while and now i have to feed to him by hand. whats wrong? why doesnt he want to eat. ive also tried cottage cheese, USED to work. whats wrong?