“We are just banging our heads against the wall. Shouldn’t we just abandon this project?”
Drive someone up the wall
To annoy or irritate someone
“Can you ask them to turn down the music? It is driving me up the wall.”
Go to the wall for someone
Support or defend someone strongly
“Fujisaki-san is an excellent boss. I would go to the wall for her.”
Hit a wall
To reach a point at which you cannot go further
“I have hit a wall on this project and must now ask for your help.” Note: Marathon runners are said to hit a wall during the race, though they often overcome it and finish the race.
Off the wall
Unusual, strange, or eccentric
“We need Hori-san on the team because she is likely to come up with ideas that are creative and off the wall.” Note: This can be used both positively and negatively. In the sample sentence, it is positive.