I'm thinking that my secret might burn me.
How could your secret burn you?
If people found out they would be disappointed in me.
I think it is ok to keep somethings secret if no one is in danger. If you need someone to confide in it might be good to seek professional help.
I think I'm about to tell someone.
It is perfectly normal to keep things to yourself. If you don't feel like sharing you shouldn't be forced to.