Disappointment is inevitable. Allow yourself time to feel sad and disappointed when things don't work out the way you planned. While allowing yourself to feel sad, also remember the sadness and disappointment are temporary. Things don't always work out the way you want, and that's okay. Disappointment is part of what it is to live, to be human, but the journey continues.
Often times, if you can get started, you're already halfway to your goal. Hesitation due to anxiety and fear of the unknown is a huge hinderance that is often based on inflated, inaccurate asumptions about "what's the worst that could happen." If you want to do something, try it! What's the worst that could happen?
Journeying the path to enlightenment, you will encounter many brick walls.
Wherever you go, you're bringing yourself with you.