manyhands, why would you think this wouldn't give us all the best impression of you ? What do you feel you have done that is so wrong ?
As far as I can see, you are trying to do the best for your little boy in trying to work out what is causing his behaviour.
Does your DS have any noticeable differences to his peers ? ie, learning difficulties, sensory or social issues, language delay etc. If so, I would personally advise you to take him to your GP and ask to be referred to a Paediatrician or CAMHs.
This was my first step. My DS was 2 when we noticed that his language was behind that of his peers. I took him to the GP who referred him to a Paed, who then referred him for a 2nd opinion. Anyway, to cut a long story short, by the time he was 3.2 we had a dx of ASD.
He is now 5.8 and attends a mainstream school. He has a statement and has 25 hours of 1:1 support at school.
However, we are now looking at the possibility of moving him to a SN school as his behaviour at school has become a worry. He is swearing, screaming, wetting himself, standing on tables, hitting and headbutting his teachers and TA's. He has been informally excluded for 2 afternoons in the last few weeks, and formally excluded for a day and a half last week. It is clearly not the right place for him as the staff do not seem to have the experience to deal with him. His behaviour at home has not changed so we know it is a reaction to something that is going on at school.
I too find his school a bit difficult to approach as sometimes feel that they somehow feel that his behaviour is my fault. I actually think that this is not the case, but as a parent of a child with "behavioural issues" you can't help but feel like that.
If I were you, I would most definitely phone the school and request a meeting like madwomanintheattic suggested, plus ask your GP for a referral to get your DS assessed, and take it from there.
In the meantime, please don't feel like you have done anything wrong. It may just be a reaction to the stress you say he has experienced at home recently, but again this is something that you can get help with.
Good luck.