I fell in love with my bestfriend in the wrong time, Advice?

I figured out I’m in love with my bestfriend right when he got a girlfriend, i feel so bad for this i don’t know if i should tell him as he has the right to know or just cut him off my life to try get over him! We’ve been friends for 7 years. I’m 21 and i feel like he is the love of my life if i lost him then I’ll never meet someone to love