It sounds like your company has bitten off more than it can chew. You didn't mention how you're doing money-wise. If you can afford it, perhaps you should stop

It sounds like your company has bitten off more than it can chew. You didn't mention how you're doing money-wise. If you can afford it, perhaps you should stop taking new clients until you've finished your current projects, and then negotiate more reasonable deadlines in the future.