You didn’t invite her to your party, so does that mean you don’t like her? No, it means you don’t consider her among you five closest friends, and you’re the type of person who prefers smaller parties. Her party isn’t going to be small. It will be bigger than perhaps you might feel comfortable with. What you’re experiencing is feeling left out and unliked and as an introvert or someone who’s not very social, this is probably a feeling you will contend with again, and so it’s time to practice acceptance. And if you can’t accept it – if you can’t accept that the price of keeping your inner circle small and not extending yourself very much beyond your inner circle means being left out of some social events – you’ll have to decide whether it’s worth it to you to be more social than you’re comfortable being. To me, it almost sounds like a win-win to not be invited to a big party when you aren’t very social. You don’t have to worry about offending someone by not accepting an invitation and you don’t have to stress about going to a party you don’t want to go to.
The people you like the best showed up for you when you invited them and wanted them to. keep strengthening those bonds and if you feel like it’s not enough friendship in your life, you can work on making more friends. But you can also work on accepting that you aren’t a very social person and that’s going to mean being left out of social events sometimes.