It's a confidence thing. A few wickets will sort his head out...
Besides, I don't see an alternative but to stick with him, he's still a potential match winner, I think you will see a big difference in the second test.
Anybody watching live in their second innings, when for about an hour no commentator said anything apart from Botham saying "he's just got to keep bowling... the only way is to get overs under his belt... he has to just bowl himself back into form... he's just got to keep bowling..."
Feckin' tedious that was. But hopefully right.
I've mention it a few times on here. . .but it's a techincal issue more than anything. He's not as perpendicular as he used to be, and tends to lean away on the point of delivery. If he can get that right, and get his action as high as he can(like it was), he'll improve and with that, gain some confidence.