Serious Question... how do I start to like "bigger people"?

I have no problem with bigger people. But ever since I was little... my mom always told me how beautiful I was because i was soo skinny, tall and elegant (i'm 5'11, size 0, 105 lbs) and I love my weight and body type. Now the bad part. My mom always, always talked bad about fat people.. I remember my older sister gaining 20 lbs to 140 and my mom called her every name in the book because she "let" herself get fat. We would go to the grocery store and my mother would point at all the "big" people and tell us to count the big "bellies" and hope we never get them. My mother would tell me that models, doctors, lawyers, actors, astronauts, CEOs, presidents,...any high job was only for skinny people and that being "big" was a guarantee failure in life. Now I have grown to sub consciously dislike "big" people because my own mother brainwashed to associate "bigness" with stupidity, laziness, uncleanness, and overall filth. I hate myself because every time I see a "big" person, I turn into an ugly judgmental person and I shun them. I don't want to be like this. I don't know how to go around the problem, I don't even know if I should get a therapist but I do know that its not normal and its not right. I have to stop myself when I catch myself being soo judgmental and stupid to even measure ones character by their weight.
Is there anything that I can do?
I know its a weird question but I really need a solution to this horrible problem.
please no rude answers.