Dont know what to feel about this situation?

Ok so basically my friend and i have been planning this summer for months and months and just as summer is around the corner, we both met this boy Josh who we both really liked. He is actually the nicest boy i have ever met but i only like him as a friend, i dont have any physical attraction to him at all. At first it was like it was going to be just the 3 of us as a trio together for summer and now it seems as if them two may be getting together as a couple. Of course, Maya is my best friend and i am so happy for her because i know it's making her happy and that they will be a really great couple but i cant help feeling a little...i dont even know what i feel...upset? jealous? Im not jealous of them as a couple, just that they have each other...i feel like i dont have anyone and that ill end up without my bestfriends during summer because they'll want to spent all their time together. It just started off with me and maya having a great summer as single ladies going out to beach parties etc and having fun and now it's all fallen apart and i feel like im being left behind a bit :/ Has anyone else been in a similar situation and can give me some adivce? Im just a little confused and upset i think x