Major major problems? Huh… Why face them and get embarrassed if you can skip it and stand straight…
Not all that your projects needs can be found in you. You’ve already exerted major major efforts to the extent of your best, and yet, it demands for more. It’s a group project after all, so it’s suppose to be the group’s embarrassment once you fail. Why work alone? What’s the sense of calling it a group if there’s only you doing the whole thing and having all receiving the credits.
While you’re getting sick of full effort, they’re enjoying with sky-limit and grades acknowledge each efforts equally. Hm hm, learn from it, and they’ll learn along with. Next time that the project is given and you know it’s gonna be a problem on your part, don’t hesitate to skip it. It’s OK not to face problems sometimes. Let the others face it for you. Let them experience the rudeness of consequence too. Let them learn how to see the essence of groupwork.