Am i overreacting

My boyfriend is 21 and im 19, and we live together. im currently doing school and i have an interview for a job on monday. He works hard and i really appreciate him i do everything i can to help out around the house and keep him happy. Is it wrong for me to be mad at him for him having woman at his job make him food and buy him food? I get mad because ive caught him being unfaithful before. And ive seen some of these girls and they are young. Theres so much more to it but Idk what to do. Am i overreacting?