New to peanut and egg allergy

Hello i am a mom for 2 boys ages 2 and 5 . My 2 year old is alleric to peanuts and eggs. we have known about peanits for awhile the eggs are new to me. I just wanted to cry when he had his reaction to peanuts.The first day My husband had given him peanut butter on toast then the next day i did and he didnt show any reaction the first day but the 2nd day didnt show one right away . The only way i found out was he had went poop and the reaction started in the diaper area it looked like he had been burnt and had hives on tummy . THank god i he went poop on way to the dr office he started turning red and coughing made it just in time. They put him in hospital just to watch for 8 hrs. But my hubby told me it was my fault cause he had the reaction when i gave him peanutbutter i told him even if u had gave him a little amount he would have had the same reaction the 2nd time .