Toddler and newborn

My son will be 2 next month on the 5th and my daughter just turned 1 month yesterday. Every time he comes around when I have baby I get so nervous and tell him be careful, watch out for the baby, be gentle and I’m starting to feel bad. I try to include him on certain things like diaper changes, giving her a kiss and just talking to her but overall I’m so scared. Idk what to do 😭