Relationships, as well as the process of meeting others, takes work. You have to be willing to accept some chance of embarrassment and rejection in order to take chances and decide who you want to put your energy towards getting to know. Once you're in a relationship, you've got to maintain it.
We all have insecurities, just some people are more forward with them than others. Some of us are awkward people by nature, but "You miss 100% of the shots you don't take."
Sometimes you'll spend a few weeks or months working up the courage to get to know someone of interest, only to have them not be available or interested. You might take interest in someone and give them your phone number, but never hear from them again. This will happen.
The most important thing is to be happy on your own, and content with your own life. If that is accomplished, then find someone who can further enrich your life. Don't look for someone who can fix you, or complete you in some way.
Be happy with yourself and the life you have. And if someone comes along and really captures your attention, go right on ahead and make a fool of yourself. And see what happens.