Everyone's experiences of chemo are a bit different but, to try to put your mind at rest (because it almost certainly won't be anywhere near as bad as you think it might be), I'll copy and paste what I wrote on Chasingcars' thread about my own experiences. (She's in a fairly situation to you at the moment):
>>> The first thing to note though is that my chemo was for Stage 4 prostate cancer (that I'm still living with, as it's not completely curable), so there might be some differences when compared to treatment for Stage 1 breast cancer. I was told that I'd have 6 sessions at three-weekly intervals. (After I'd had 6 though, the consultant said that I could stop if I really wanted to but he'd rather that I tried for 10. Given that the chemo nurses had told me that it was totally impossible for anyone to get through more than 8 sessions at the mega-high dose that I was on, as people's bodies simply couldn't take it, I wasn't exactly pleased at the prospect of another 4 sessions but I got through them in the end).
The other thing to say is that everyone is different and two people having identical treatments might experience very different side effects. Having got that lot out of the way though, here's my input (which is based not only upon my own experiences but also upon those of other people that I spoke to during my chemo sessions):
If you have chemo you will, undoubtedly, experience some side effects. However don't allow yourself to be scared by the full list of possible side effects that you'll probably be given in a leaflet or booklet. You'll only have very few of them.
The one that probably worries people the most is nausea. (Nobody exactly relishes the thought of continually feeling sick for several months in a row). However, while a small percentage of people might be unlucky in that respect, most people seem to have very little, if any nausea at all. I didn't experience a single moment of queasiness throughout any of my sessions or after them. Further, you'll get anti-nausea treatment during your chemo session and anti-nausea drugs to take after them as well.
The only problems I had with my digestive tract were incredible heartburn (which was easily and fully treated with omeprazole) and severe constipation (which was fully dealt with by an over-the-counter product, Laxido, from my local pharmacy).
One 'almost certain' side effect of chemo is hair loss. Even so, the timing and extent can vary widely between patients. I had a lady friend who had chemo but didn't start to lose any hair until a few weeks after her treatments had ended (and she didn't lose very much of it). I, on the other hand, found that my hair was falling out just two or three days after my first session. Despite that, I still kept much of the hair that was left on my head anyway (as I have male pattern baldness), while losing hair from everywhere else on my body. (Getting on for two years after my chemo, I've still hardly got any eyebrows or eyelashes). During my chemo sessions, I met some fellow patients who still appeared to have a full head of hair, while others were totally bald, so it does vary quite a lot.
The other 'almost certain' side effect is tiredness. I certainly experienced plenty of that and most other people seemed to as well. I got through it easily enough though by simply sleeping whenever I wanted to, and for however long I felt like, which usually left me with plenty of energy during my waking hours.
As I was on a 'maximum dose' treatment, I also experienced a bit of 'chemo brain', leading to mild forgetfulness or confusion but I doubt very much that you'd have any similar problems.
The actual chemo sessions themselves are very easy. You simply sit in a nice comfy chair, wearing your normal clothes. After asking you a few questions, to check that they've got the right patient and to check up on how you've been faring since your previous session, the nurse puts a heated pad around one of your hands, to make it easy . . .