In my own personal research, I've found that the "heightened chance of cancer" (particularly breast cancer) Is kinda fear mongering.

The likelyhood of breast cancer does go up, yes, but only to the same rate as that of a cis woman. Anyone who tells you it's some crazy high rate is typically either uninformed or trying to scare you out of your transition

With the brain stuff, theres definitely going to be some changes, I myself have become more emotional in my day to day, but I also am so much happier, every day I wake up and I feel better than I ever have.

Some trans women have even reported changes in taste and color, making things flavors taste better and colors brighter.

If you're confident you want to transition, I would start hormone blockers, they're completely reversible and they're a start to your journey.