"don't leave me.stay with me".How can i say this?

Tweet

I have falled in love with gary for more than two years.He is a good guy,i love him so much and i know that he also loves me. But he will go abroad to America after 2 or 3 months,then stay there to study for three years at least.I'm so sad and I can't go with him. Another thing worried me is that my parents ask me to find a boyfrind as soon as possible.(I didn't told my parents I have boyfrind now, gary and I considered that it's not the right time to let them know.) I want to ask him not to go,ask him to stay here with me.But how can I?It's good to his future,so how can I stop him?