Screwed? Nah, but it will be a challenge. You've gotta sqeeze every bit of worth out of your units, and use your generals as liberally as possible too. Those guys will grow back as long as the character doesn't die, remember. The best thing is that you can concentrate all your efforts on the north. Try to find one of your two enemies allies, and ally with them - one of the two might come over to your side in time. Then focus on taking out the other one.