Be practical. tell him you are very concerned that you grades have fallen from A's to C's and you'd like a tutorial or at least a brief discussion with him, to take you through the problems he sees with your work, and what he expects from his students. Then listen and take notes. Don't say much except thank you, unless it's clear that he's misbehaving in some way. Don't flirt or dress up or wear much make up. If you are normally dressy tone it down a bit - he's a capricorn - a goat and you are there only to ask his advice.
If he's mean and unhelpful during the tutorial, make notes of that; unprofessional behaviour can be made know to the college authorities. He may just have very high standards but there are always known critieria for marking essays and he should be able to tell you what these are and how you can improve your performance. As a cancerian you should have some degree of rapport with him but don't take what he says personally unless, of course, it is personal.
If this is happening to a lot of people, and you all think it's nasty behaviour, go to see the college authorities as a group. He may be depressed if he's just been divorced but he shouldn't be taking it out on his students and may need help himself, If he won't help you, again, look for aid in the college system; tell them your concerns - there is a higher authority than this man and he may already be known to them Do tread carefully
Good luck - another female cancerian and ex-lecturer.