Password Reset Issue

I use Apple Mail to view my Comcast messages.  I've been unable to get access to it for the past couple days as it's asking for my password.  I haven't done anything to the account so was surprised and thought it was just a glitch.  However, we're going on a 2nd day now so decided to try logging in through Comcast/Xfinity website using my Comcast email and was asked to reset my password.  I entered the username and it then asked for mobile #.  When I originally set this up, I used a land line.  It didn't recognize the number and I was told to contract support.  I refuse to call Comcast support as it's a nightmare.  Can you help me reset my password?