Sorry to hear yet another has been diagnosed with bc. Do you have someone you can leave the kids with while you have chemo? It is very nice to have a support person with you during the hours sitting there and a second pair of ears for your appointments as you won't pick up on half of what is said, its just so overwhelming.
You won't need the gym but cycling is doable. The only thing is be very careful of the sun. Your skin just won't take much of it during chemo at all. Possibly by the time you get to work cycling, you won't have the energy left to do any work so maybe you could organise a lift for those days? Some days are fine on chemo and some are just flat out on bed days. There doesn't seem to be a written pattern to it at all so stay flexible with work.
Kids are very adaptable. Let them nurse you and do little things for you if they want to. It will help them to cope. Just make them understand mums a bit sick now but she will get better; its just going to take quite a while. Hugz XXXX