I'm sorry that you're struggling so much right now but, believe me, what you are feeling right now is a battle between you and the fear. We have all been here! You must continue to tell yourself that this is the fear talking, trying to bully you into self doubt and despair. Challenge those thoughts! Where's the evidence for the anxious thoughts? It really helps me to dialogue in my head (or out loud for that matter, but perhaps not in public!) with the fear which I have chosen to visualise as a very clever bully who is trying really hard to find a weakness in me and play with it. I will literally say, "O.K., so your back. What are you trying to sell me today? Well guess what buddy, I'm stronger than you think and I will ride this awful feeling you are giving me but I will hang on and prove you wrong. Your not as powerful as I am and I am going to hang on until you leave." May sound weird but it's really important to understand that fear is powerful and an expert at finding our weaknesses BUT we are more powerful and will find a way to kick this bully out of our system. It will feel awful for awhile but as long as you document your anxious thougths and the evidence against them you have begun gathering evidence to fight that bully!
Another thing that really works for me is that I made a "Feel Good Book." I bought a sketch book with balnk pages and I only put things in there that I love and make me feel good. Include the times when you were successful at proving the fear wrong! I have pictures of people I love or admire, scenes that calm me, quotes from friends or books, leaves...you get the idea. Really what I'm trying to tell you is try anything and everything that builds strength and slef-esteem. You can so this! Try not to avoid the fear but build a case against it!