Despair is the diametric opposite of everything in which we believe
—in other words: it is a denial of reality.
It is a denial that there is a G‑d who directs all of His creation, and watches over every individual, and assists each one in what he must accomplish . . .

Who said that life is going to be perfect? We know since the exist of the Gan Eden, that we will have to work hard and confront hardships, while there are a lot of possibilities given human imagination, we should know that all comes from H'. Humans are built with many emotions ( including despair,) and those emotions serve us to deal with events and relationships. Yet, anything we confront, it will be easier if we remind ourselves that "Gam ze Ya'avor, ( this shall also pass! ) ; and keep going forward. That leads me to argue let us not be prisoners of the past- because past events are the main reasons of that despair! It comes to mind the life of Yitzhak Perlman: he ended up with a disability when young that probably caused him despair, but found a way to go forward. He is great example of how to confront life. Focusing on our strengths even when life is not easy. Find support if needed, and trust that H' is with us. Kadima!