My friends are annoying!

I have these girl friends who annoy the sh*t out of me. I can’t seem to be rude and tell them I don’t want to talk to them! They are constantly trying to make plans with me and I have been pushing the excuses quite a bit, do you know if there is anything I can say and not sound rude? I think they know I don’t really care about our friendship as much since they have told me I am distant… they are not rude or anything, just really annoying. I think in some ways I haven’t really been rude because I don’t have too many friends… but I just feel as though they annoy me. They constantly want to go to clubs and I feel we do not have anything in common anymore. I feel bad even thinking this way because they are nice to me, and I am the one who always seems to come off as rude, I’m just really puzzled as to why they continue to want to hang out and not see that I have been avoiding them. One of them also complains that I rather go to see my boyfriend (I have been with my boyfriend longer than good friend with her). I find that they are clingy and I want to somehow get out of this without coming off as rude. Please help, I am really a nice person, I;m just stuck in a weird situation. Plus there is no category for this so I had to choose love and relationships :S Anyway maybe there is someone here who can let me know what to do, thanks.