Starting soon

I am starting my sophomore year on the 13th. I am excited but nervous at the same time. I have no classes with my boyfriend and almost all of my classes with my guy bestie. My boyfriend hates him. But me and my bestie have been friends since 3rd grade. My boyfriend doesn’t like that I talk to him. And stuff went on between us. My friend admitted to me that he liked me and tried to take me away from my boyfriend. But me and my bestie made up. He even has a new girl. What should I do? And how do I convince my boyfriend that there is nothing to worry about?