I’m a teacher with add – see both sides. Even if your son is only angry at himself – it is still very scary to others – when someone is out of control, it can be frightening esp if teacher can’t control child. So don’t underplay it – if someone at your work went off – you wouldn’t likely get close either.
To get friends – be a friend. Find someone on baseball team to come over – I’m sure some parents could use a break and let you have their kid for a hour or two. If not…then take an honest look at your child – perhaps needs more help than just a therapist? Social skills?
Your child’s teacher should be able to give you some insights.
good luck and good job for getting him in sports (that’s why Michael Phelps got into swimming). It’s important for add kids or anyone with spec needs to have something they are good at!