4 year old son ADHD and Sensory Seeking Behaviour

My son who will turn 4 in a couple of months seems to be a possible ADHD and SSB kid. The Kindergarten he goes to has been complaining about his hyperactivity - He cannot sit still, is super active, inability to complete tasks assigned, work in a team... They say he is very sweet, very bright and even when he seems to be not listening, he picks up everything being told. He seems to not like writing. In the coming months, he will start regular school and I am worried that he might not fit into the school routine and his progress will be affected.

He was born in C-sec, 2.5kgs. He has not had any issues as a baby worth mentioning. He is currently 14kgs, thin and tall for his age. He gains weight very slowly. He is a picky eater and does not like most vegetables - unless it is cooked and mashed into his food. He hates fruits and will not eat it in any form.

He has met all his development milestones on time. He struggles to wait his turn in conversation so will interrupt others to say what he wants to say. He also struggles with queuing. He loves animals especially dogs and cats and is not scared even when they are barking or hissing at him. He is very sociable and confident and will talk to anyone.At school and in the park he plays alone or no one will play with him because he seems to like aggressive games. His favourite play is crashing cars.
He likes to act silly in an attempt to make us laugh and then will keep repeating it. He is impulsive and quite often acts the class clown and will act in a silly manner when he is with friends. They seem to wind each other up to fever pitch and his voice will get louder and louder and he often shouts, become a little rude and stop listening completely and act up! He also has a very loud speaking voice (no volume control), so you can always hear him above everyone else! He is very sensitive and empathic and hates to upset people. He is very aware of hurting other’s feelings and hates to think he has done so, although sometimes he will do this unthinkingly because of acting silly or due to lack of impulse control!

All his waking up hours revolve around vehicles. He can name all the trucks and sometimes imagines himself to be "pickup truck, Fork lift or Excavator" and starts acting like one. He is always climbing and loves jumping from high surfaces onto beds and sofas. Even if he hurts himself- he continues doing it. His pain tolerance is also surprisingly high- he does not cry for most bumps and hits and shrugs it off.
He is not an aggressive child- does not throw much tantrums or be obstinate. But he just does not seem to know how to play with other kids. He is pushing and walking purposefully into them, sometimes grinding his teeth. He sometimes seems absent when looking at you as well, as if he is not really present and will then physically shake himself to bring himself back into focus!

He likes playing in mud and water. He is always chewing onto things- his clothes, fingers, objects... He crashes into people for hugs and does not seem to realise that he is hurting people.
His sleep pattern is very poor. Falls asleep after a very long time and gets up very fast.
His kindergarten has been suggesting that we take him to Psychiatrist and start medication- which I am scared to.

I am hoping with all my hope that there is something in Homeopathy that can help my little guy. it breaks my heart to see him struggling and I don't want him to be kicked out of his new school and be ostracised in class and be disliked by his friends and teachers.
Please please help me .