Talk to Pediatrician on Breathlessness

My son who is about 4 years old started having breathing difficulty 3 months after birth. One day he was crying and for 1 minute he did not breathe, he turned blue and black, then this happens sometimes, once he had this problem even while sleeping, then that day when he was doing rounds, suddenly he got breathless from his mouth, and his eyes started drooping and he was not able to speak, then he got fine later, last night he was coughing repeatedly, he woke up from sleep, he was coughing but he was not able to cough properly, his eyes were red and blooming out showing difficulty in breathing, first I gave him water, I breathed him through my mouth but he was not opening his mouth, I slightly pressed him on heart again and again,then after some time he got fine, then he slept but the cough did not come again. Please tell me what is the matter, which doctor should I show it to for treatment??