This is a disaster for the whole GOP, but especially for McCarthy—but then again, he was a disaster when he ran for Speaker seven years ago, too.
The far right has him by the short and curlies. He could try to win by shoveling more and more concessions to them, which he very well may, in which case they get a disproportionate amount of power and look like golden gods in the press. If he gives up, they get their way and somebody closer to them (Steve Scalise, for example) instead. If he courts the Democrats, or they court him, or if he does something wacky like order twelve of his acolytes to vote "Present," he is well and truly finished not just in this Congress, but in the primary pulverization he'll suffer in the elections just NEXT YEAR.
And the longer it goes on, the more their base loves them for their obstinance.
He lost two days ago. Now, he, and the twenty far-right goons pushing this, are just hurting the party, the House, the government, and the American people. His best path now is to step aside, let someone else take center stage, and retire to the position he is best suited for, that of a rank and file Representative. Maybe he'll get lucky and get a committee post.