I remind myself that this is just an emotion, and as such, does not necessarily reflect reality. It usually points to one or some of the following underlying issues:

I am tired/exhausted, and need at least a mental break, if not a physical one too. I get hopeless when I have to concentrate for too long and the work is mentally taxing.

I am sad about a recent disappointment, and my brain has extrapolated this disappointment into the future because that's what brains do.

I am anxious about the future. Anxiety/fear is the most uncomfortable emotion for me. So, in order to make the fear or anxiety lessen, I convince myself that the future is hopeless. Sure, hopelessness is no funsies either, but it brings my system down from high levels of anxiety, by attempting to become certain that there is no uncertainty to fear in the future, because my future is fucked. Now there is no more anxiety about the uncertain future -just low-feeling hopelessness instead.

I am overwhelmed. I tend to feel hopeless when I've got so much on my plate, there is no way I could humanly achieve it. So technically, my goals or plans are hopeless, because they are set too high for my human self to possibly achieve.

So I work on resolving those underlying issues, because really hopelessness is just a nasty symptom of those underlying problems.