Outburst from 14 year old

So I'm struggling a bit. My 14 year old is in therapy. I made some post last month but he was a victim of a crime recently which is what he is recieved therapy for. I'm the mama that made the post about my 17 year old letting my 14 year old sleep in his bed because he couldn't sleep since he kept having nightmares about the man who victimized him. His behavior has changed a lot which I expected. I had to make him delete social media because on Facebook they post about recent arrests and there were a few comments victim blaming my son under the guys mug shot. He really likes his therapist. She's really great with him. But I'm dealing with some behavioral issues where he has these outbursts over silly things end sometimes in public. He acts juvenile and he eventually realizes how immature and embarrassing his behavior was. An example is we went to boofest in our town. He was tired because we had been out all day at the pumpkin patch with my sister and her kids. We were waiting for the costume contest for my nieces and he started saying this was dumb and he wanted to go home. I said we would. He started having a miniature temper tantrum saying he wants to go home and he's tired. I told him we would go home soon and to stop acting like this because he's 14 not 4. He yelled at the top of his lungs IDC! And that he hates it here. It's hot and he's tired. I told him to quit making a scene. So he just kept whining and we just left. He went to his brother's room to take a nap and did apologize to me later. This is a thing that is becoming common and I'm not sure how to handle it. Especially when people are staring which they were. A LOT. His therapist said they can work on coping skills for when his feelings are getting flooded. I don't know how to handle this in public. A few times my oldest has just walked my younger one somewhere else to calm down. I know a change in behavior is normal with trauma. Just trying to navigate everything.

@Mommaof4: I'm not trying to come off as defensive and I hope my reply doesn't but I do feel a little mom shamed. He never said he didn't want to go to boofest and we go every year. It's not even scary. They have a trunk or treat with food trucks and a lot of vendors and rents where you can buy things like honey straight from our home town and they were also selling freeze dried candy. It wasn't haunted House themed. Was just a little festival. He wasn't upset because he was scared. We had just been out all day and he was tired. I would never intentionally take him somewhere that would hurt him or cause him trauma! Ever! He loves Halloween