Dropped the bike, now it is constantly shutting off

I was going slow right turn after red light and hit some sand and went down gracefully. Code 30 as usual, but this time it's on concrete road and not dirt. Nothing broke or out of ordinary so I kept going. A few minutes later the bike started showing sign of shutting off at low-medium speed. By that I mean 1 digit to ~30kmph (20mph). The symptom is pretty simple. It is similar to a carburated bike running out of fuel. Sometime it dies completely, sometime it comes back to life like it was just some revving interruptions. And this only happens at the speed mentioned above. Anywhere over that (ripping it!!!) and it's totally fine.

Interesting part is, it's not just engine dying. It's the whole bike shutting down, and then restart itself. Imagine riding with speed and then turn the key off (not kill switch. but the actual key itself) then turn it back on, it's exactly the same. EXCEPT that sometime the engine/temp/gas light icons that turn up when we turn the key on while fuel pump priming, sometime they light up for a while normally (as if i twist the key off and on) and sometime they don't. And sometime they show up and disappear immediately. Best way to describe it is "dashboard twitching".

What I've thought about after some googling:
- fuel pump issue: it's 2010 model and fuel pump still priming just fine. And this issue happens both cool and warm.
- kickstand sensor: it kills the engine but it shouldn't kill my dash so i doubt it.
- dirty kill switch: same thing. it shouldn't twitch my dash.
- ignition key messed up: i turned the key off, then back on, dozens of time, and it lights up those bunch of icons normally. but when my issue happens mid ride, sometime those light don't show up. this is why I doubt this is the cause.
- battery: even though i haven't measure anything yet, the bike idle for 15mn without any sign of problem on light/signal/etc. or runs at speed above 30kmph without any sign of problem. only in between.

So the only way I could make it back home, tested it out last night, and back to work again this morning, was by trying to make it past ~30kmph (sometime when it hiccups it can throw me off badly with 1st/2nd gear's engine brake), and then i can just rip it and it runs like nothing wrong at all. But when i get stuck in traffic (South East Asia btw), it would die constantly every 2-10s, sometime longer than if i'm lucky, it's totally random.