No, you haven't.
You may have exhausted your patience.
You may have used up your willingness to look for a solution.
You may even have used up whatever hope you had.
But that doesn't mean that you've exhausted the possibilities, or that you need to quit. You may need to take a break to re-think the shape and size of the problem. You may need to make a conscious decision that your obstinacy is going to be bigger than the obstacle. You may even have to face the fact that you don't want to have to dig as deep or be as strong as you need to be.
Too often discouragement is a bigger issue than whatever 'real' problem we face. And I think it's worth asking why. Why do we fan our fears instead of stoking our determination?