People around you would support you when you are in the process of achieving something because they see themselves in you who is struggling, showing commitment and discipline, ambitious and goal oriented. But people would drag you down and try to attack you when you achieved something and reached higher standards than the people around because now you remind themselves of their failures, laziness and lack of commitment. You did something that others also can do but they did not due to some odd reasons. This creates a sense of shame and guilt around you.
People are just protecting themselves of the shame and guilt by demeaning you and rejecting your achievements. Generally people do it consciously or unconsciously in the name of your best interests because it is easier to diminish others hard work in stead of puttin gin hard work to become better one self.