I feel like a fraud

The first time I saw my oncologist, he said: " you are going to die, I cannot fix it, I cannot operate. The question is when. What Ican do is make you more comfortable and try to prolong your life".So I have had 2 cycles of chemo 3rd starting Thursday, plus pain drugs and although I have some skin problems , physically I look the same as ever, I still have my hair , I haven't had any significant weight loss and the tumours have shrunk significantly which means the treatment is doing what it set out to do. I think it makes it hard for my family to comprehend that I am sick. I do feel quite well during the week I don't have chemo, just tired a lot, not too much pain, but I am discovering that my body is much more limited in what it can do. I keep having to tell people to slow down when walking as I cannot keep up with them.So yes there are unseen signs that I feel but not much outward ones, which really makes me feel like a fraud.
When I read about what a lot of you are going through, I think I am really lucky so far and hope it stays this way, I just wish you all had an easier ride. Reading your stories makes me stronger and a little ashamed about my feelings. I hope I will grow to have your courage.
Sylvie