For me, I ask myself, ...how many years have I been trying to go out and could never do it? How many more years do I want to do it? ...the answer was obvious...being scared and not going out has not helped me feel better (for years), so the only alternative was to change it. I went out, I could say I overcame my fear! And I felt better.
Another way to put it, what if you felt regret on your final death bed for not doing it all your life...you could be gone tomorrow...so do it now. If it doesn't work out, no big loss at least you won't reget not doing it.