Any tips for dealing with anxiety while at work?

I have just started a new job and feel like pooh, I just keep worrying that I am under performing, which is obviously not going to help.

Plus I suffer with health anxiety issues which just makes things even more difficult to deal with as everything gets blown out of proportion even down to the smallest thing can start a panic attack.

So anyone got any tips for dealing with this at work ?

Just re-started my medication thsi week, so hopefully things will brighten up soon :(