Why won't Google and some other secure sites load?

I'm having trouble loading Google and some other secure sites on my MacBook (late 2006 model running Mac OS X 10.7.5 Lion). What's really annoying is that it works on other computers on the same wi-fi network, my home wi-fi network, and works on my own computer on the student wi-fi at school perfectly fine. Google and related apps, like Google Drive, load only rarely, and then they keep losing connection. Other secure websites also have trouble, like Facebook. However, it seems like Facebook loads more easily than Google. I also tried loading Google Drive on the administrator account of my computer, and everything worked fine. It started doing this about a week ago, and I'm not sure if it's because my mom turned on Parental Controls right around when the problem started or not. The thing is, right now, Parental Controls are completely off (not just allowing unrestricted internet access), and it still doesn't work consistently. And, again, it's only on my own account, and it's only on my home wi-fi. Also, this is happening with Safari, Chrome, and Firefox, so it's not a browser-specific problem, either. This is affecting my school work because I'm trying to do a colloborative project, so this is actually a big problem.Do you have any suggestions? Thanks!