I have no qualms about getting asked about the gap or short duration of my employment because I am sure most will on some level be able to empathize with my situation. It's the idea of automated filtering machines or some person who has to go through 100s of CVs a day filtering me out without giving me a chance to explain that worries me. But that's a chance I'll simply have to take, I suppose.

What you mention about your current employer is eerily like the situation that ultimately led to every aspect of being just giving up. My last place of employment was an electronics startup making a portable version of an Amazon Go store. I joined fairly early and worked on pretty much every aspect from programming arduinos to migrating an old version of the web application, the mobile app and server code. I used to work about 17 hours a day and initially I really enjoyed solving all these different problems. But it eventually got to a point where those were the only problems I could solve and it ultimately came to a head, oddly enough, when I was buying milk at a store. I bought 2 packets and knowing how much 1 packet cost I couldn't calculate the cost of 2 packets. I just broke down right there and knew I needed to take a break. The feeling that I could write a daemon to reconfigure iptables rules on the fly without referring a manual but not multiply a small number by 2 is shattering.