you will be ok - brain mets won't kill you!

But it is time you re-assess your treatment and maintenance strategy - whatever you were doing prior to brain mets, seems not good enough to keep cancer under control.
Once you are through with this mets /headache /wbr thing, i suggest you take a serious look into comprehensive /alternative treatment options. By that, I don't mean chinese medicine (or more appropriately "cheaternese medicebo"). I mean COMPREHENSIVE western medicine plus individualized nutrition, plus immune building and revitalization, plus detoxification, etc. Raymond Chang of nyc is highly recommended by many long term cancer survivors - a number of them had had brain mets just like you.
raymond chang