I find it best, when I start to worry, to get up and do something. Disengage with the computer and do something like go for a walk, or do some chores, or if you're at work, take a walk to the bathroom or chat with a coworker. Hobbies that involve both the body and the mind are helpful—so cooking, gardening, doing puzzles, painting/drawing, these kinds of thing—anything that distracts the mind long enough so that you don't fall down the rabbit hole of googling. This isn't an exact science or anything, and it doesn't mean you'll feel amazing or that the anxiety won't be there, but it should help you from panicking and running to the internet.
I had one therapist tell me that when I started to get scared, to think about a time in my life that was exciting or I had the chance to do something cool/out of the ordinary. So, for instance, I'd think about a trip I took or a time I had some personal or professional achievement, etc.
Remember, the anxiety you're feeling is just the body's NORMAL reaction to stress. We don't help it by catastrophizing, and we certainly don't help it with the negative reinforcement behaviors. So it will take you quite a while (it was months for me) of doing all the "right things" to really feel better, because those stress hormones that are so high in your body need to be brought back down to normal levels. But, it can be done, as I and others on the AZ can attest.