Feeling pressure

I lost my job because the company was cutting costs. I had no idea the company was in financial trouble, and they never warned me that my position might be at risk, so I didn’t have time to prepare. They told me the same day and let me go without any notice, which felt very sudden and upsetting.
I’ve been under a lot of stress because I feel like I should already have another job, even though it’s only been a couple of days since I lost this one. It’s really affecting my health. I feel a lot of anxiety, and sometimes I get short of breath and have panic attacks. My appetite has finally started to come back, but I still have trouble sleeping some nights.
I feel like there’s so much to do, like fixing my résumé and cover letter. I’ve already started working on them, but I still feel a lot of pressure, like I should be employed and back at work right away.
Right now, I feel like a big failure, and it makes me feel worthless, like the world doesn’t need me anymore. I’ve always been dedicated to my field.
I’m giving it my all, but it’s just really tough right now.