Don't be shy! Do come into office hours with questions -- it's never too late for me to help you.
Drop-in-tutoring is available at the Student Learning Center, and is a great potential first place to look for outside help.
There are so many online resources that I cannot even begin to list them all; MIT's Open Courseware is a fantastic resource, not just for this class, but many others. If you would like more online resources for a particular topic and are having trouble finding them, feel free to email me — I would be happy to try my luck online as well.