How do I stop being anxious about my best friend/ex-partner (19NB) from an online relationship coming to stay with me (18F)?

One of my online friends has been my BEST friend for almost three years now, and we tried an online-LD relationship to no avail last summer. They're from another country and we've already met once, which was in February when we spent the day together. It was so wonderful! Now I live in my own place and they're coming to the States for a few weeks and asked to spent a week with me-- and ofc I said yes! I miss seeing them in-person and I cannot pass up an opportunity to see them.

I'm not nervous about them staying with me but I'm nervous about my parents. They don't know about my friend and I feel like this isn't something I can hide from them. I'm an adult so it shouldn't matter, but I'm afraid they're going to be REALLY upset about it. I want to keep it a secret but that feels like too much hassle. I don't know if my dad will have an issue but I'm afraid my mom will make a big deal about the fact that I kept a secret friend from her, plus she has MAJOR issues with online friendships.

Another issue is my other college friend was coming to visit during the week my ex is coming, and I had to tell her I can only spend the day with her (instead of spending the night). She was really sad to hear that and I feel really bad about blowing her off, but I can see her almost any time I want.

I don't know how to stop being anxious about my parents' reaction and my friend. It's consuming my mind. Is there any advice you have to help calm me down?