What Causes Excessive Crying And Lack Of Appetite In Infant?

My 4 week old baby is crying too much at night lately, he was ok 1 week back, I am using formula (similac) for him because I cant feed cause I have hypertension and drs gave me meds that are not ok for feeding. He often spits out milk and when he is streching or moves he makes some growling sounds I dont know if its colic Or something. Hope you can give me advice. Thank you