I am about to allocate ~100% of my liquid cash for a masters degree ☠️ 

And I don't even need that degree for work, I just always wanted to do it. it feels like now or never

I did this in the past, completing a second degree (while still working), no work or financial benefit, just for me.
Go for it, you only live once!

I need that environment tbh. The ROI is shit, but this isn't an investment for me.

This is just what I want to do

No real regrets, would do again. First one Applied Science and then later, Info Tech with some focus on expert systems.
Easy to underestimate the study, work, life balance. 
If you have the resources for f/t study, go for it, although AI is changing so rapidly. Consider the ROI, so much info  online now for self learning

Interesting, how it went and what you studied?