What if I’m just questioning?

I have been doing really good for about two weeks. but today has been really hard. my boyfriend and i have been really good and having a great few weeks, but i’m terrified it’s going to change. i’m scared i’m just in denial and i am actually questioning mt sexuality. i’m scared that if i have sexual fantasies, it means i’m that orientation. i’m terrified i was actually in love with my ex best friend, and i didn’t realize it. we had a really strong connection, and i’m scared i actually liked her. i’m scared i’m repressing my sexuality, and that i’m lying to myself and my boyfriend. i don’t want to one day wake up and realize i don’t love him, or that i’m a lesbian. i just want to be happy with him and love him