I cannot log into m Gmail account. It gets stuck on the loading page. Please help!?

I've been using Gmail since it first came out. I've had problems in the past that fixed themselves. This has been hapening for a week and I cannot find what to do.

When I go to Gmail, no matter if I type it in go through my account, etc. The white page with the word loading comes up. Then it just keeps switching the URL back and forth to something, to fast to read. In the lower left corner it will say done and then swtich to something else I cannot read. It just keeps doing this as long as I leave the screen up.

Also, sometimes when I type in Gmail it says the security certificate has expired. I am able to get into my account from another computer, just not the laptop I normally use.

I've emptied temp files and history twice. I haven't deleted cookies though. If I do this will I lose all the passwords I have stored?

I read someone changed their system time in order for it work, but I'm not sure what that means.

Google emailed once, but it didn't work, emailed back no reply.