Say to your mind, "Get as depressed as you want. I am only going to observe you, but I am not going to join you."
Day in, day out the voice in my head attacks me. "There is no way that your investment case is true", it says. Or, "the loudest ducks at work will get all the credit, while you get none". The institution in my head also calculates for me in how many years I shall be bankrupt once I lose my job. I better stop here; I guess you get the picture.
But what happens instead? I get dressed the next morning, show up at work and do my thing as I do every day. Whether I am successful at work, or whether the pessimistic voice gets its way, I don't know. But there shall always be a next day when I get dressed and try again. The only thing I do know is that the holy Now calls all the shots, not the internal nay-sayer; the voice in the head can only provide the commentary along the Way, but otherwise has no authority over me whatsoever.
There is total freedom in the holy Now. Whatever it is you focus on at this moment, give it your best shot and let a higher authority evaluate the significance of your contribution. The holy Now sets you free. Observe for yourself how the voice quiets down in the heat of the moment.
Abundance is of the Way, scarcity is of the ego. Just do your thing, walk away and let the results speak for themselves. Tao travelers also have doubts, but moment by moment. we shall be free.