Happy yet Sad

I just found out that my best friend from high school is engaged. It's a weird situation to be in. I'm really happy for her but at the same time I'm sad for me. I know that it should be all about her but I'm having a hard time not feeling sorry for me. A lot happened and we are no longer friends we are more acquaintances now. I want to be able to celebrate with her, go to the reception and give her a big hug and say congratulations but I don't know if I'm going to be able to have that opportunity. I don't know if she'll want me to come to the wedding reception or not. It's a situation that I never thought we would be in and we are and I just don't know how it will turn out, but I don't want her to doubt for a second that I am beyond happy for her she truly deserves the best.