Hey. It's really shitty that on top of fighting for your life, you gotta deal with dysphoria, too. It's not fair, and I'm so sorry.
I wore a lot of cute fem knit hats when I went through chemo, and that helped. I also leaned into clothes that emphasized my beautiful new-to-me fem figure, so if someone was going to misgender me it would have to be on purpose because they were an asshole and I didn't care what they thought.
Surprisingly, my loving spouse taking lots of pictures helped a lot, then, and later. I was surprised by how fem I looked even when all I could think about was my big lumpy dome and face elbow that other people called a nose (it's smaller than my dad's cis wife's, but try telling my brain that).
Hopefully this helps. You are beautiful.
Fuck cancer. Send cancer into the fucking sun. I believe in you.
Ps: there are LGBTQIA cancer support groups out ther, and they can really help. Here's one such org.
https://www.cancer-network.org/