Yes, you can kill him. It is just not a very well tuned encounter. Make sure not to disengage him as this would reset his HP and you would have to start all over again. Also you can time your attacks to the moment when he attacks, this will cause his attack not to land. If you need time for the potion cooldown to come down, you can run circles around him. I changed a lot of the AI already so in a post-jam build combat should be more enjoyable.
Thanks for playing and the feedback.