Rashi on Numbers 22:3/רש"י על במדבר כ״ב:ג׳

1ויגר is an expression signifying fear, as in (Job. 19:29): “Be ye afraid (גורו‎)" .

2ויקץ מואב means they (Moab) were sick of their lives (the expression is similar to קצתי בחיי in Genesis 27:46, being an abbreviated form of it).