Is it normal that i want to ditch my dependent bff?

I have a way weird friendship with my "best friend" which was formed basically on the fact we only had each other and no friends. We used to hang out every single day and hed always want to hang out with me bc he have a lot in common. He has never admitted it to me and has denied when I ask, but i know he has some serious social issues that he deals with. He once even confided in me he thought it was really nice of me to be literally his only link to the outside world, since his issuses forced him to drop out of high school.

After about a year of being really good friends, he got a job, which would considerably cut down time we hung out together. Ever since he started his job, he has adopted completely unreasonable attitudes about the real world; ie, that he is the jaw droppingly handsome, and that everyone loves him. He now acts like he is really really cool, and has pretty much stopped hanging out with me. We hang out about once every 2 weeks now. I know that I am literally still his only friend, although he tells me about the seas of offers he apparently gets from his co-workers to do things socially. He has adopted completely new political ideals that verge on the radical, now denounces all the things we both liked as something he NEVER liked, and generally has a really shitty attitude. This summer, he has bailed on me everytime I call him to make plans. He claims he is just really good at being alone, but what has pretty much happened is he hangs out with his little brothers everyday all day in lew of replacing me with an actual peer/friend, in order to feed his new persona of "popular".

We start college next year (the same one) and I really don't want him in my life any longer. He has said it would not be an issue if we were no longer friends, that he works well alone and can manage with no-one but hes not taking into account the social interaction he has with his brothers. I love him so much because we have been best friends for a long time, yet I dont want to be friends with him anymore. I'm really worried tho, that if I just cut him off, something really really bad could happen.

I know this friendship isn't normal, but do you think I should let the friendship continue to die until its gone or try to keep it up and help him out?