Re: important, need to know what to do!
Why do you assume that if you have a brain tumor you are going to die? Many people have brain tumors that are benign, but even benign ones can cause tons of symptoms.
If you didn't have kids, I'd say it's your own business if you want to stick your head in the sand and likely miss out on your chance to cure this (if it is brain cancer). But since you have a daughter, you should be thinking more about her and how this would effect her.
Even if your daughter is little, what do you think she would say if you told her all this? Would she want you to fight? I'm betting the answer is yes. She has a right to have you on this earth as long as possible. Can you imagine someone having to tell her that you are dying? Because that would be what would happen. With a brain tumor, you won't be able to just hide away and pretend it isn't there. You will eventually lose it, and someone will have you put in the hospital until you die. People with brain tumors become extremely belligerent and even violent towards the end, and they don't even know it.
At the very least, your daughter deserves closure and a chance to say goodbye. If you do have a terminal illness, it will be very hard but you will have to tell your daughter. I have known people who had a parent with a terminal illness, where the parent hid it from the child. Even into adulthood, that child hurt so much not just from losing his mother, but from not having the chance to say goodbye to her. All of this is very painful, but hiding it so you don't have to *see* your daughter's pain is not really an option.
You gonna have to cowboy (or cowgirl) up. And if you are facing the end, remember what Dr. Seuss said: "Don't cry because it's over. Smile because it happened."