2 year old son got his first shot of dupixent please give me hope with any stories ??

My son has severe eczema so we finally got him the dupixent shot of 200 it’s been about a week and seems to be making his flaring up so much worse but not as bad as itching but the flare ups are all over his lefts which he never usually had it all over like that is this normal ?? He is 2.5lbs weighs 28lbs I’m so scared to even do the second shot if it potentially could make it worse and also have been reading it could possibly trigger psoriasis ): I feel so guilty if I thought this shot was the right thing to do ):