You really need to get medical advice about this - explain your concerns to your team.
I had a different type of cancer (oesophageal) and could have had my eggs frozen but that was extra time that I was not getting chemo and my cancer is known for being very aggressive - I took the chemo and do not regret it...having said that I am now expecting (was 32 at diagnosis and am 35 now)...you have to make the decision that will make your long term treatment bearable.