When you look at the modem status page (192.168.100.1) in your web browser is everything green or are there issues in there? Have you tried unplugging the power from your modem and router and then reconnect after about 5min? I know that sound like the normal run around but some times that does fix the issue. I would check the modem status page first though and look at the lights on the modem and make sure they look normal and are all on.
Could you please send me an email at firstname.lastname@example.org? Please include either your account number or a phone number tied to your account. I'd like to take a look and see if we can help you get back online