write down on one side on a page all the positive things about going back to work.
Then write down all the negative things. Then look at which ones are external things (like ''I will enjoy the money'') and which factors are 'internal' things like ''I will feel scared''.
You will notice that most of the negative things are 'internal'....
We all feel like this about new sitations, eeryone at your workplace will have been a new person, worrying about will they like the pople and vice versa.
Tummy problems - take some immodium or whatever with you.
Learn to smile. (everyone likes a cheerful soul)
Learn to breathe properly (deeply through the nose, out through the mouth)
Wear a bracelet to fiddle with if neccessary.
Take a notebook and write stuff down, it gves you something to focis on and people will just think you're being dedicated and enthusiastic.
They will most probably give you a couple of days induction where nothing too strenous is expected of you.
Good luck, it may well be the making of you x