Anyone else feel like an impostor?

Like whenever I mention that I have cancer I feel like I'm faking it or something because like I went through radiation but still have hair, and I don't have any of the "usual" cancer symptoms. But then I also feel like I'm being dishonest and hiding things by not disclosing it?

I just switched jobs, and haven't really said anything to anyone about it at my new job. But I need a total neck dissection, and that's kinda not going to fly under the radar with me working in a hospital. I left my email nonspecific, stating I need a surgery, had a similar surgery done earlier this year, (TT in May) and don't expect the recovery period to be very extended, but I'm willing to meet in person to discuss it further.

How much detail should I even go into? I HATE the pity look when I say it's cancer. Almost as much as I HATE hearing "oh it's not like a bad cancer." Like I get I'm probably not going to die but let's not compare cancers ok? Nobody ever wins that shitty contest. But then I also feel like I shouldn't hide that I have cancer. It's a fucked up circle.