I'm not gonna introduce too much but I hope this helps you <3
1- Love your flaws, so nobody will have nothing on you.
2- Everyday, before you get out of your house, stand in front of the mirror and say things like "i'm beautiful", "I deserve to be loved", "I am important", and things like taht.
3-Trust your capabilities.
4- Take risks.
5- Try to show you're confident even if you aren't. Will help you to understand that is ok to be confident.
6- Recognize your talents and good qualities.
8- Repeat this everyday.
Just remember I'm not an expert in this subject but I'm just trying to help you!
See you soon! Xx