How Do I Treat Fake People Who Want To Suck My Blood?

I have a draining issue. Im a pretty nice person that has a hard time being mean to people. i consider myself to also be a very good friend. the last two years has brought me a lot of new financial success. i do not brag and i like to live humble and share my success with friends. but i notice a lot of my "friends" hardly come around or keep me in the loop anymore unless they need something. i also notice how some people used to be snobbish or just didnt like me for their own personal reason who all put on a great performance now. they say how great i am and go out of their way to be kind to me. you never forget how people treated you before and sometimes it bothers you. i dont want to be egotistical or mean so what does a person in my situation do to keep real friends in my circle and the fake blood sucking actors out of it?