As @zoffiel says - all too common. I started with a lumpectomy and maybe rads, then ended up with a second surgery for mastectomy followed by chemo and radiation. It does take the wind out of you but it is doable. Ask about a port - it's well worth it in the end. I went private for oncology as it was covered by health insurance but public for radiation (and that was as good as any private clinic could provide). Radiation is not covered by health insurance and it can cost thousands. I can't remember everything I got in preparation for chemo but you will find lists on previous posts here (beginning of 2018 for sure as that was when people helped me). It's good to have the stuff on hand particularly if you're not in easy reach of supermarkets/pharmacies.
I found this in an earlier discussion - info I had passed on to someone else back in 2018 based on what I had used:
"Before I started, many members shared there must-haves list with me so I could stock up in advance as we don't live near any shops or 24/7 pharmacies. You can probably find the post - would have been February I think... But here is what I have found useful so far to have on hand:
Sorbolene (for dry skin in many areas)
Dove soap
Very soft little kids toothbrush
Biotene mouthwash
Baby shampoo and afro comb to take care of your hair if you're keeping it - I started with cold caps
Coloxyl with Senna
Movicol
Pocket sized sanitiser lotion
Large antibacterial wipes for public loos
Pocket sized wipes for whenever
Mylanta double strength for indigestion
Truckload of Panadol for headaches
Flushable bottom wipes for when things get tender.
I haven't used all things all of the time but everything except the Movicol has had more than one go and most have been regularly reached for."
I would also suggest that you make sure you have a decent thermometer on hand at home.
If you're not going to try cold caps for chemo, don't rush out and buy a wig as they are expensive and you may find you hardly wear it.. There's lots of stuff online for interesting ways of tying scarves and with winter coming up (and isolation, of course) you can hide under hats if you want to. If you do feel the need to wig it, find out if there are any wig libraries you can access.
If you haven't done so already, you may find it useful to collect and collate your medical notes and reports. They pretty quickly assume a life of their own and start multiplying. I got myself a zip-up folder from Officeworks (and very quickly updated to a lever arch version) plus some plastic sleeves and dividers. I kept everything in there including appointment cards and prescriptions so everything was together and it was portable.
As for timeframe - it will depend on the chemo and whatever is going on with isolation. I had AC-T and that took 6 months. 4 x AC every 3 weeks then 12 x Taxol every week. A couple of weeks rest after that followed by 3 weeks of radiation (15 doses). Pretty standard treatment. How you tolerate it is an individual thing and you won't know until you start but please don't go on what you see in the movies as a guide. Medications are pretty good at handling side effects as long as you let your onc know what is going on. I suffered in silence for the first few days as it was a weekend and I knew no better. Once the onc knew how bad I was feeling, he prescribed better meds that got me through it. Given that, some people sail through the experience (well, perhaps not sail, but they cope well). Keep a running record somewhere handy - times, symptoms, medication, temperature... It helps you keep track of things, provides a guide for next treatment, and helps to report back to your onc what has been happening.
Also, think of practical things you may need help with. It's not helpful if you get given a freezer full of meals you don't want when really, what you need is a lift to and from the hospital, or someone to feed the animals for the first few days after treatment. That way, if people say they want to help, you have something immediate to suggest. My lifelines were the friends who picked up my kids from school without concern or who stepped in to drive one across town to a sports carnival while I was having treatment.
You will probably find you have more questions as things become clearer. The most important thing for you to remember is that this can be done - it's not fun but you will get through it. And take care of yourself.