My advice might not be helpful for everyone but it's what works for me: just do it. I know it isn't that simple, but you really do just have to do it. Even if you panic. For me, after going outside and staying out for a bit, the anxiety and fear dissipates

After a traumatic event (any) our body and mind tries to find coping mechanisms. My was so bad that I didn't wanted to leave the house because I was afraid of people. Even now a days I do try to go out every day for five minutes but COVID didn't helped at all. I found much easier do to baby steps, 5 minutes to see the sun and go back to the house. Coping day by day