Jo jo

Hi I am wondering if anyone can offer some advice. I have a child in my class who is very bright and making good progress academically, however there are many occasions when he is overwhelmed by his emotions. His reactions to tiny incidents are extreme. For example when a child bumped him, accidentally, he wasn't hurt but he screamed like he had broken his arm. ' He cries sometimes when watching numberblocks, he can cry at lunch time, when he is asked to do something. However these reactions are completely random, no pattern, some days fine other days not. Parent have said he is very confident at home. I have seen evidence of this through our remote learning sessions. However at school he struggles to cope. He is very passive and tends to play alone. I am aware this is sounding like it could be SEN or attachment issues and this is of course being monitored. However we all know how overstretched services are so I am unlikely to get any support for him (especially as he is making progress). I was just wondering if anyone had any ideas of how I can support this child right now. Have you had a child like this what worked to support them? Most of the time he says he is tired when we ask what may have upset him. We are working on him expressing his feelings. Now we have had another lockdown this could be worse when we return. Any advice greatly appreciated!