Connections with Xfinity and Facetime

I’m unable to to use FaceTime with my Xfinity account, Xfinity mobile. I have very few bars most of the time with the exception of right now which is very rare. I live in Sacramento County, lots of towers, I’m on autopay, always paid in time and have a horrible time with low connectivity. In a large city it should not be this way. Haven’t been able to use FaceTime for a long time. Only tried a few times off and on the last 8 months. Have tried more just to see why I’m unable to connect. Same way. Was told I have to have an account in order to have FaceTime…? An account with Xfinity or with Apple? Customer Service closed right now. I have an Apple ID and paying Xfinity. Is there something I’m missing? Could I have some ID theft going on. Something I’m unaware of? Possibly through another account, possibly hacked through email or some other spyware. I’m no up to date on technology. I’m 65 and have no help. This doesn’t make sense. I feel I might have someone else using my Apple ID. How can I fix this?