Exercise is supposed to release endorphins and make you feel good so why do I feel worse afterward?

I guess I have depression tendencies but when I'm away at school I never workout and feel terrible most of the time. But I'm on spring break and for the past week my mom has taken me to the gym everyday but for the past 2 days I've felt worse after working out. Why? :(
Exercise is supposed to release endorphins and make you feel good so why do I feel worse afterward?
Post Opinion