First reaction?

Mason had what we think was his first reaction this weekend. He had been tolerating the 6ml dose just fine. Then yesterday, Saturday, we went up to the 7ml dose. We waited for our rest period. He had a big dinner and went on the trampoline with his little bro and cousin. We didn't realize how much he ate and within a few minutes he wasn't feeling well. He complained of his tummy hurting.
Some time went by with no improvement and we chalked it up to jumping on the trampoline after eating too much.
5 hours had passed since his dose and he threw up! Then the throwing up would continue on and off for 4 hours into the night. Long after we went to bed we would keep waking up to be with him.
This morning he woke up fine, just really hungry. He seemed to improve during the day and then it was dose time. I gave him the 7ml and within the hour he didn't feel good. I decided to text our doctor and catch him up on last night and now today. Was last night really a reaction to his dose or was it really eating too much and jumping? Was he not feeling well today because of his dose or was it because he didn't eat enough today to handle his dose? It's such a cycle and guessing game. He decided to play it safe and back up off the dosage amount a little bit. He told me to give Mason Benadryl today and again tomorrow before his dose. We are going down to 3ml and working our way back to 6ml where he was good before. His normal 2 week appointment this week is being rescheduled for next week.  (Also, thankful he didn't go into anaphylaxis.)
So far today and tonight, no throwing up, so hopefully we all get some sleep tonight!