I have a hard time making decisions because I have so much doubt. What can I do to be more sure of myself?

Believe it or not, it all boils down to not having enough self-love.

Because self love gives rise to confidence. Confidence gives rise to courage. Courage gives the ability to take risks.

Since in the end, you make the best choice you can and take action. If it doesn't work, you do something else; no big deal.
But you have to free yourself from fear; fear of failure, of other people's opinions, and anything else.

And all of that starts (and ends, really) with a healthy sense of self-love:
http://su.pr/726uK5

Ask me anything