Hello! I think almost everyone who has issues with anxiety (including me), has negative or unusual thoughts. But these are just thoughts only because our minds are racing out of control and at the moment we can't control it. Try using some type of distractions. That's what I do to keep my mind busy.
I have learned that the busier I stay, the better off I am. Think of things that have made you happy in the past and as soon as you have the negative thought, replace it with your happy thoughts.
Also, if you live near a library, maybe you should try checking out an anxiety book. I am not a reader at all, but I think I am going to do this sometime this week.
Good luck with everything!!