In love with my friend and it’s intense

I’m (21nb) so in love with my friend I feel physically sick. This happened 2 years ago, I told them I liked them, they didn’t like me back + it was a bad time for them, we had some space, came back together again, and my feelings have returned. I can’t be normal around them. I say things I regret, I keep trying to perform and prove myself to them, and then I beat myself up afterwards. It’s making me unwell. We’ve just got back from holiday together and I feel like I want to curl up into a ball and cry. I don’t know what to do with these intense feelings. I don’t know how to just value them as a friend because this isn’t healthy. Hopefully this is the right sub to post this in.