It is highly unlikely that you are imagining that your throat and mouth are numb. In order to do that, you would be looking at another mental health issue, and even that is rare. Because you are already anxious and have had panic attacks, it is almost a guarantee to be from anxiety. Anxiety can cause odd sensations and make you feel certain ways. But it is usually from your nervous system responding to your anxiety and not your imagination.
That is a good thing! If it was another disorder, it would be harder to treat. I know you feel very frightened right now and you wonder why you can't feel like you used to. But I can promise you that if you continue to work on your anxiety, you will feel better and feel normal again.
Focusing on how you feel is going to keep your anxiety up. You are scaring yourself with your thoughts, which is making you feel even more frightened. Although it is hard to let go of these thoughts, it will help you a lot to try to focus on the fact that this is only anxiety, and although it feels horrible, it will not hurt you. It is only a feeling. Yes it can cause your body to feel odd sensations, but those will not hurt you either. Repeat that to yourself as much as you can. And if you have other people you can rely on, try asking them to reassure you. Make a list of reassuring statements to keep with you and read them over and over. This will help you change your thoughts.
You may also want to read Hope and Help for Your Nerves by Claire Weekes. She has an excellent way of addressing any physical symptoms that you have because of anxiety.
And I am here for you too. Anytime you need to talk, just let me know.