Samantha & the others are exactly right, the whole chemo ride can be a bit up and down, and you need to do what's right for you. I agree that it's good to ask for what you need -- whether that's company, or a phone call, or a hug.
Amanda (I think?) reckons you need to think of chemo like a pac-man, munching through your system. If you feel a bit crap, take comfort in what it's doing to those pesky cancer cells.
You don't need to be fearful so long as your medical team is available -- they will help you get thru it and try to minimise whatever side effects you experience. Personally I've had a couple of rough cycles but each time the next one is much better, because they can alter the dose and/or give you different medicines for side effects. If fearfulness isn't helpful to you, acknowledge it and let it go.
Also Tonya (I think?) says that if you're very anxious, you can ask for a 'calm-me-down' pill -- if that's what you need, ask for it.
Good luck to all of you just starting chemo. Nearly everyone here has some tips and tricks for managing side effects, so come back & tell us how you're getting on. Go well,
Heather