Pain while urinating. Pic for reference)

My baby is 19 months old. For the past 5days in the morning he cries heavily while urinating. He is very scared to urinate. And the first couple of urine are smelling very bad. And after that he urinating very often in less amounts.. So i thought to not use Diapers (i use diaper only at nights). But what i noted during that diaper-free night is, he is not at all urinating whole night. But before and all he had very good heavy wet diaper. Now he is not urinating at night also.. So at morning he is crying very badly at first urine. Iam really worried of my baby.. Please some one help me. Points to note: He is not circumcised. He did not had any urinating problem from birth. His urine is smelling bad. No fever. He cries heavily only for 2-3urine at morning.. After that he doest cry. And especially i noted that his urine is changed to thick. And i observed some white patches after he urinated in mat. (attaching pic for reference)