"Although beauty may be in the eye of the beholder, the feeling of being beautiful exists solely in the mind of the beheld." - Martha Beck
Hello - As Martha Beck puts it, beauty is something you believe. There are people that will find you attractive and as you said, there are people that find you unattractive, but what do you think about yourself? That is what matters. When you begin to believe that you are beautiful/handsome, then YOU ARE!
You don't need people to tell you that.
And people may treat attractive people different than others, but it also depends on your level of self-esteem. People feed off of the energy that you have, if you walk around as if you are ugly, and like you don't deserve better treatment, then people will treat you that way.
I know this to be true because I consider myself to be a beautiful woman, but at one point in my life, my self esteem was shot, and it showed. People treated me like dirt, they barely spoke, and they barely paid attention to me. But now, that I have confidence, I walk into a room and I demand their attention because I know within myself, I am worth being paid attention to. And it's not about my beauty, my body, or anything superficial like that, it's about me - as a person - and the asset I am to this world. Looks fade - but the gift that your existence is to the world, can last forever.
So - believe in yourself, believe that you are attractive (inwardly and outwardly), believe that you are worth good treatment and act accordingly. You can do it!