Needing desperate advice.

I’m a year 11 student at an all girls school. I have many friends and get along with many people but as the year has been going along I realise more and more than I’m not getting invited to their birthday parties. I’ve been depressed for a while now and this is just adding on to it. And out of one of my “closest” friends, she invited people over to her house on the weekend but not me. Am I that bad to be around? I just feel like if I died no one would care. No one would notice. But then they would all pretend that they cared and they were super nice to me. I don’t want to continue living like this