Plants are orders of magnitude more complex than microorganisms and we "intentionally kill/enslave" them in huge amounts. If you think it's ethically questionable to "enslave" microorganisms, what do you think of eating plant based food, and how do you propose we live?
It’s the fact that there’s no good answer that makes it a dilemma
The fact that you don't have an alternative other than suicide removes much of the dilemma..
No, that’s precisely what creates the dilemma - do you have a moral or ethical right to take the life of a sentient being to save your own? Do you have a right to do so repeatedly over time? What makes your life worth more than those you’re taking?