I'm in love and I'm trying very hard not to say it
Why don't you want to say you are in love?
Because I'm very afraid of rejection and if they say they don't like me back it would make my heart suffer
It is scary to tell people how you feel but  holding your feelings in is bad. It can sometimes explode out of you when you least expect it.
I don't want them to look down on me and that's why I don't want to talk about my feelings.
But don't you want to potentially have a relationship? You'll never know if you don't try, and I believe it's better to take the risk and know the outcome instead of wondering forever about the what-if! I'm sure they would appreciate you being sensitive and talking about it.