5 months pregnant jumping over the sofa 😩

I'm currently pregnant with my 3rd a little girl I have a son who is 8 and a little girl who is 5, my daughter is autistic and was in the middle of having a meltdown so I asked my little boy to put my takeaway in the kitchen next to the microwave, now he's very helpful and hubby has been teaching him how to warm up his milk so breakfast so him trying to be helpful but my Chinese (foil container) in the microwave I've never jumped so fast in my life I had to jump over the sofa in the kitchen and lucky the flames were small and easy to put out I've never been so scared in my life ever little mans been very upset since, He feels so bad and keeps saying I was only trying to help. How do I make him feel better I've explained the dangers to him and told him it wasn't his fault but he is still extremely upset and sat alone in his room