First of all, Mamanan, take a nice deep breath and purse your lips and slowly blow the air out. Do this a couple of times and you will feel some of the stress leaving you.
Now, anxiety. I had anxiety before fibro...kind of like what you have. It was like an adrenalin rush if I was frightened or worried about something. Then, one day in church, I had my first attack...for no reason! I won't describe the symptoms because, right now, you will take on anything I may suggest to you. But, they frightened me so much that I didn't move for several days until I could see a doctor. I though I was having a stroke.
I saw the doctor and when he told me it was anxiety, I felt so much better. He put me on Valium and I was having to take so much of it that it was changing my personality and it was making me groggy. I didn't like that at all and found that all I was thinking about was how I was feeling. I finally realized that anxiety is fear and I really didn't have anything to be afraid of. I had just been checked out by the doctor. I would conger things up in my mind and scare myself to death....just what you are doing. So I decided I needed to get control over this and I stopped the Valium.
I already knew what anxiety could do to my body and how I felt. I was sooo familiar with the racing heart, the breaking out in sweats, and all the other things that would follow those initial symptoms. When they would come on, I would do breathing exercises and dismiss the symptoms because, after all, they were just symptoms of anxiety. Then I would get busy doing something else...clean, read a book, turn on a movie. After a few minutes I would find I was feeling better. It did take a little practice but now I really have control over anxiety.
It will still try to rear it's ugly head but I know how to handle it. If I have something that might not be anxiety-caused, I'll check it out with my doctor...like when I first started having heart palpitaions. I was thoroughly checked out and my heart was fine. They are a symptom of fibro and anxiety so now when they happen and anxiety wants to kick in, I don't give them a thought and get busy doing something else.
Have you seen your doctor about your facial pain? You probably have mentioned it but I read so many post that I can't keep them all straight in my mind. If not, get checked out. The sore throat and swallowing could easy be sinus drainage. I get that. Our sinuses can do a lot of draining with all the weather changes and rain in the summer months and this seems to be when it started for you. If you have swallowing problems, cough. That should clear it up. It could just be mucous in the back of your throat. Again, that happened to me.
The nausea and having no appetite can be anxiety. When that first happened to me, before I got a handle on anxiety, I had myself at death's door! 
I look back on it and just shake my head. I am a strong personality but yet anxiety was tossing me around like a featherweight...until I finally put my foot down and would not put up with the terrible feelings it was giving me. Feelings that made me feel totally dibilated...feelings that really had no basis in what my overall health really was!
You are dwelling too much on how you feel and then your mind congers up terrible illnesses and that increases the anxiety and that also increases the symptoms. Anxiety can totally be dibilating. Don't allow that. You are a strong woman and you can get control over this.
Anxiety lies to your body and makes it think it's sick. So, get a physical and, when you get your clean bill of health, kick anxiety to the curb. NOW you will know what is REALLY causing the terrible symptoms you are feeling and you can stop it in it's tracks.
By the way, check out the scripture in my signature. It's my dealing with anxiety that had me put that in my signature.
Sherrine