Well - there are walls for every horse. But sounds like you need a break from whatever you are doing. Some horses process things at different rates. As many posts above mine state.
I used to have an Egyptian Arab, smart as a whip. But he would have his days, or maybe they were my overeager days. But anyways, we seemed to have a disconnect with learning half passes and lateral moves. At that time I was not super smart about stopping before an argument ensued. But I did have enough sense to realize we weren't being productive.
The hardest part was learning to let it go, take a break and give my head and bruised heart a chance to move into a better mood.
I often found though, that after leaving a session and giving him a day, the next time we worked, he would give me what I was so desperately trying to get him to do the session before, without much prompting.
What this comes down to - take a break, maybe you are trying to hard, you want it so bad to work. Just do something fun for a few days, maybe take him for a walk down the road, without reins and a bit. Get some confidence back into yourself and him.
When you start up - hopefully you will have a better frame of mind and heart. And so will he.