i used to make little diagrams on my test when I first sat down to help me remember things maybe you could do the same.
I would also study the problems I lost points on to see if there was a common thread to my mistakes. Spend more time on these problems but not so much time that you forget the others.
You could try standing up and teaching it to another student on the whiteboard and then see where you get stuck.
What are the key things you forget, write them down and carry them with you. At test time, write them down on your test for fast lookup. Find a simple version of the volumes of revolution problems, replay them in your mind so you'll have something to latch on to.
Sometimes, you can use the test to help you remember. You don't have to start at problem 1 and work your way to the end. Scan the test front to back then do the problems you know and your test anxiety will drop and you'll remember better. Its the anxiety that's making you forget.