Hi Jensen
I remember feeling just the way you do. The short and possibly unhelpful answer is that you may not know if you can continue working until you start treatment. It's not so much about immunity as to how you feel yourself. Some people work right through - I did, and the only germs I had to contend with were my own (small problem with fluid build up!). I too wore a wig. All my colleagues knew I was having treatment because I told them, but it wasn't obvious to anyone else. I looked well and my "hair" was much more attractive than my frizzy locks when my own hair started to grow back (it was very welcome all the same).
But I had no nausea, no aching, no fatigue. All of these can knock people about. A flexible work place is a wonderful start. Plan to work, but plan to make changes if they are necessary. 6 months sounds forever but it will pass. Good luck.