Somewhere along the way I always lose my friends?

Long story short, I've been super shy my whole life but it's gotten better this past year. I'm currently a sophomore and I have made some new "friends" this year, or at least a group of people I hang out with at lunch and stuff. But somehow I can't help feeling like I'm always being pushed out of the circle, and that they don't want me there.. there is one girl in the group I'm closer to than everyone else but whenever she starts talking to someone else she ditches me. I feel like as soon as I have a "good" day a bad day follows. It just feels so stressful for me to keep friendships going, because whatever I do people always see me as weird and awkward. And it just makes me depressed and therefore I have no motivation to try to keep the potential friendship going. They're all really close with each other and go over to each others houses all the time and stuff, and I'm just that weird girl that sits at their lunch table.. sometimes I cant even get a word in and sometimes when I walk up to them no one even says hi to me.. I even made them all goodie bags for Christmas and they still ignore me. I feel like they think I'm stupid or not capable of talking about the things they do, but I'm just too shy and no one is like, guiding me into the group which is just what I need right now. I feel like I'm alone at school all the time even when I am surrounded by people.. I never have any plans on the weekends and it's been half a year since I started hanging around these people at school. I thought my friendships with everyone would progress really fast but apparently not.. I feel so lonely and depressed all the time, sometimes when I walk by someone in my "group" and they used to say hi to me, they don't even see me any more and continue to look for their other friends. I don't belong anywhere, and the scary thing is I feel like it's just because of me! Sorry this is so long.. help??