To give up or keep trying is the exact topic of The Dip, By: Seth Godin.
I think this question fundamentally boils down to two points.
First, you have to decide what kind of person you want to become.
Second, if you are making monthly, quarterly, annual progress – something – in your area of identity (above), you have to keep going. Right?
Or, I don’t know…
If you are doing the right thing – the thing in your heart – maybe you don’t worry about the outcome?
I wish I could ask the future whether I should give up or keep trying. Then again, what if trying, even in the face of certain failure, feels as good as accomplishing? What if it’s even better? And here we are again.