切る => Give up, stop... N3
Happens next
切る/切れる/切れない => to do something completely to the end/unable to do; too much to finish/complete N3
[後「あと」]で => After V1, V2 N5
Time
〜がさいご(が最後) => if you do... negative result N1
Decisive (resolute decision)
[切「き」]れない => Can't finish/complete A N3
Potential, Possibility
たが[最後「さいご」] => Once A occurs, B happens N1
Information, Report
~をかわきりに(~を皮切りに)      => One after another; starting with ~ N1