The girl i like said no because im younger, help?

[Jacob]

The girl i like likes me back. I've wanted to date her for 2 years. She had a boyfriend during that period. Now shes single so i asked her but she said no bc shes going to a different school next year & im gonna still be here. We only live 11 mins apart. She also said no bc after she leaves we're barely gonna see eachother. Shes only 11 months older than me & she wants someone her age. Bc they bullied her for dating someone a year younger than her. She likes me & says she would say yes but those issues. Theres this guy whos basically my competition. Hes her age & likes her. She likes him but she said she wouldnt go out w. Him bc she doesnt want to hurt my feelings. I just dont know what to do. I easily get jealous when she talks to guys especially my competition. Idk if i should keep trying, or just let her go. She says that in the future she'll marry me & all that. I need help. So help me please? I would like a girls P.O.V &. A guys P.O.V