Have been always anxious, nevous and aggressive. Do you have any suggestions?

Hello doctor,

I have a 6.5 years old boy. The boy was born with c-section and apgar score was low immediately after delivery but improved in the following measurements. He lived with us at home. In the period from 2009 to 2012 his social life was limited because we stayed away from our home town. His rapport with other kids was very limited ane then improved after 2012. The boy is always anxious, nervous and aggressive at home with his younger brother and mother. When we go out, he cannot interact with strangers easily. Even with cousins he does not interact properly, especially in the absence of us. I note in the last few months that he always puts his nails inside his mouth and there is noticable damage to his nails. He started to go to school two weeks ago, but he does not like school as well. The teacher says that he always follows her and cries even during break time. We really have difficult time with him. His academic level at school is the lowest among other children. I do not know what is the probable diagnosis for his case. I have tried to book an appointment with qualified psychiatrist here but no available doctor until the end of this month. Today I went to pick him up from school and he was crying there and when we arrived home he was hungry and he refused to tell us anything about school. So we asked his elder cousin who said he cried the whole day and was following the teacher. Teacher also told me the same thing and he is not able to concentrate in the lessons. I hope you can find a solution for the problem of our child. Do you suggest using medicine, behavioural therapy or any other suggestions?