Hello wouldrather 
- sorry you find yourself here, it is all rather scary and you've had an awful lot happen to you (and you life has changed radically!) in the last couple of months - its a lot to get your head round so you are bound to feel wobbly.
As others have said - first chemo is hard because its fear of the unknown and dealing with all the conotations of 'chemo'
I think everyones mentioned most of what I'd suggest (so apologies if I repeat)
Something to read, or listen to on ipod (audiobooks are good if you like them) - you'll have one arm out of action so anything that requires two hands is out.
Snacks and drinks of your choice - hospital will provide sandwiches, and tea/coffee, - if you like herbal tea take a teabag along and they'll make you one. I preferred to take my own things - bits of died fruit, little tomatoes, nuts - nibbly stuff.
First chemo takes a bit longer than subsequent ones, because they will watch for reactions, and will be explaining it all to you, and there are sometimes delays in getting in to the unit, - have you got someone going with you for company/moral support?
I'd take a cardi to wrap round your shoulders - it can get cold sitting in one place, but you need something you can take off with a line in your arm. I don't know of you have a picc line or are having a canula when you get there. If the second, - having warm hands and wrists makes it easier to find a vein - so I used to wear gloves and wrist warmers in the car and waiting room.
If I think of anything else, I'll repost.
I think one of the fears for me daft as it sounds, was the idea of 'going into a room full of people with cancer having cancer treatment' but everyone is very friendly and kind and you will honestly get used to the routine of it.
They'll give you a bag of medication to take home, make sure you have the unit/hospital number handy by your phone in case you need to contact them with enquiries before your next cycle.
I found it handy to jot down my symptoms and side effects in a little notebook each day, because they'll ask you about them next time and if you know how you felt each day you can be given stuff to deal with problems. If you feel very sick, ring them and let them know - they can give you something to help,- don't put up with any side effects, - they can give you something to help with most of them Good luck!
Sorry - that's one of my massive essays again! - waving to everyone, - sorry you had a bad night Gigs, hope you're feeling a bit better now, what did you put on your list in the end? 