Stop crying?

Selfpost on a throwaway account. I need some help... Ever since i was a child i cried about everything like not getting this or getting a scrape on my arm. Well i'm 17 now and i don't cry from physical pain anymore but i'm emotionally weak. For example, I didn't cry when i broke my arm last year but when people saw me in pain in the ER or in a vulnerable state; that made me cry. I even have a loving girlfriend that has been with me for almost a year but when we fight and when i feel bad i end up crying and make things worse by making her feel bad. I can't help it and when i look back i tell my self that's a stupid thing to cry about and tell myself to harden the fuck up. But it never sticks and i forget those facts when i feel sad the next time. So i need your help reddit. What are somethings that i could do to keep myself from crying?