I'm not able to change my skin because of the security questions

I recently bought a new computer and am playing minecraft on it normally, but yesterday i tried to change my skin and the launcher asked my answers to the security questions, but i forgot the answer to one and so i was unable to change my skin. So i tried to change the questions, but after trying twice, they didn't change so i'm stuck on the past questions. I waited until today to the questions change and so far it hasn't changed. What should I do?