If by "last day" you mean the day before today, then always use "yesterday". However, if it is from a time further in the past, eg. the final day of your time in the desert, then use "the last day".
Interesting use of "seduced" - it doesn't have a sense of desperation, but instead instinct convinced you bit by bit that you should eventually kill.
The "-duc-" in seduced is the same in "educate": Latin "ducere", to lead. So by being seduced, you were led or guided to your action, not driven or forced.
For Richard: the comma would divide up the sentence, however your examples are already clear without the comma. So it's a matter of taste. :)