If you are really concerned then go and talk to your CGI and discuss delaying your sitting. You're not one of ours because we don't have a course sitting next month, but I am sure other schools also encourage students who are not ready to take another month, until they are happier. The CGI should also be able to give you more advice about whether you really are as far behind as you think, and may be able to offer you more tuition (if not, get in touch).