Remember that God is sovereign. He is still in control and His ultimate purposes and glory will not be thwarted by anything. No disappointments or mishaps take Him by surprise. If our theology of God is right, we ought to never lose hope.
Are there disappointments and discouragements in unmet goals? Yes. We can learn from the difficulties and apply that growth in wisdom and humility and holiness to the next focus. If we have made a good effort and things don’t turn out the way we thought, we still cling to God and to principles from His word as we continue to try to please Him in everything.
A dear friend quotes: “When the horse dies, dismount.” In the words of a once-popular book on Christian leadership: “Sacred Cows Make Gourmet Burgers.” Don’t despair! But do move on! Take the things you’ve learned and use them for God’s glory in the next endeavor. People will fail; circumstances will change; doors may close; but God’s purposes will ultimately prevail; Christ will build His church. Jesus wins!