I would cancel your score, if you completed so few questions of the last section and feel like you did poorly.
Additionally, you may be able to file a testing complaint against the proctor:
http://talk.collegeconfidential.com/sat-act-tests-test-preparation/726791-reporting-a-proctor.html
“All you have to do is call CB Customer Service (1-866-756-7346) and tell them that you want to file a complaint. Explain your situation to the agent, and they will file the complaint for you. You’ll need to tell the agent the test center you took the test at and what happened, and if anyone else was affected. You have until the Wednesday after the test to file a test complaint”
Maybe call about the complaint first, to see if they offer you a redo or a refund or whatnot.