Sorry to hear this.
Stage 2 means it is still localised, right? It may have been found in time and is treatable.
I don’t know about your uncles cancer or what stage it was but not all cancers are the same and some are very treatable. In one type of cancer, survival after 5 years is 99% for stage 1, 95% for stage 2, 50-6i% for stage 3 etc. Stage 2 can be a very winnable battle. Even stage 3 can be a worthwhile battle.
You may be avoiding a very winnable battle in which you can have a long and enjoyable life after some short term discomfort. Some cancers can he treated in a localised manner with radiotherapy rather than chemo.
I implore you to verify what the treatment options are and success rates before making a hasty and final decision.
A relative of mine came back from stage 2 doing pretty well and is pretty happy after a year of treatment. Some of it obviously a little challengeing, but they have no regrets.
Best to just lead with the facts. “Due to having issues with x, y and z, I went to the doctor. After further investigation it has been confirmed as stage 2 xxxxxx cancer. I’m still trying to understand more about it.”
As another poster said, give them time to emotionally process this. They care about you so are naturally going to be affected and that is fine. Doing this in person is preferable.