I transferred from my village to a town for 5th grade and didn't really fit in so got bullied a lot. Worst I had is having thoughts that I am worse then everybody else and of course I had a lot of trouble with confidence.
At some point I just looked at myself in the mirror and said to myself that I am the best in the world, I didn't believe it of course but still kept saying that. After that it was just a long Journey of pushing myself to do something when I can and it got me to where I am today it took me around 8 years I guess, I still wouldn't call myself overly confident but I follow principle fake it till you make it and put myself in situations when there is no going back, got job I like, girlfriend and overall I am happy with my situation. It's still never easy but while I don't have a lot of confidence or willpower I always had ambition and desire just to be a better.
What do I mean pushing myself when I can? Here are some of my achievements over 8 year period:
Writing to a girl from class, nothing flirtatious just SMS'ing.
Going MMA classes around 12 grade, still doing that since I enjoy fighting a lot when it's all friendly., however I was always got panic attack when actual conflict ensued, not sure how I would handle it now.
Going to bigger city for studies.
Going to study for half a year to Portugal
Inviting girl for a dance at the bar
Starting a talk with a girl on a bus or on the train. Done it around 4 times I think, no dates came out of those but still pretty proud.
Signing up and going to a Job interview.
inviting girl for a date.
Most of those were extremely awkward and with little result, however still quite proud of them.