In order to be able to deal with emotions ,a person has to be comfortable with fear. Everyone fears. The success lies in taking the risk and overcoming your fear. 

Even if you're not able to achieve what you want at once,you now know what must be done and what went wrong. The next thing is  to be patient with oneself. To achieve something you must keep on trying consistantly. Someday or the other , you will achieve your goal.

The third thing is to stop comparing yourself with others.It doesn't matter what others have done. What matters is what you want. The main thing is whether you are happy at the end. 

Fourth is to be proud of what and who you are. There is no need to be uncomfortable or insecure. Almighty made you who you are because He is aware of what's best for you.

Last but not the least is to remember that no one is perfect. Everyone makes mistakes. Learning from those mistakes, forgiving yourself,moving on and growing is what matters. Instead of mourning over what you don't have ,you must learn to be grateful for what you do.

These can be called a few ways to control your emotions by being self-confident.