if the partition really doesnt exist then you either deleted the partition or destroyed the partition table. either way, if you dont have important data on it then id recommend you just abandon the install, delete everything and make a new one. otherwise you could try your hand at some linux file recovery tools (windows ones are almost certainly a scam).
been a while since i done this so i might have gotten some parts wrong:
get a thumbdrive/usb drive/whatever you call it
install the arch iso on it. im assuming you still have another device you can boot to.
plug in the usb into your broken device. turn it on. then boot into that usb. you probably did this while installing arch so im assuming you know how to do that.
once in, mount your broken arch install by doing mount /dev/ /mnt. take note of the space between the partition and the /mnt.
then do arch-chroot /mnt
from there just install grub like normal (just do whatever you did to get grub working in the first place).
i use trime on android and the default takes quite a while to get used to. for example, the symbol key that is usually on the bottom left corner is now a language switching key and the symbol key is one tiny key beside it. custom configuration seems like a pain and i haven't done it. one of the defaults however comes with a menu that lets you type all sorts of symbols including greek, russian, japanese, IPA and mathematical operators. haven't sen fcitx5 for android though
edit: currently using fcitx5 android and i can say just go with this. everything comes right out of the box (no screwing around with config files) and has all the features trime has and more (i can even type unicode! ☻). only feature i would miss is that trime types both round brackets at once and places your cursor in the middle whereas fcitx5 android needs you to type them individually.
only difference between billionaires and normal people is that billionaires have a lot of money. best not to assume they have above-average logo appreciation skills. although they could hire some good advisors i suppose
alright now we're gonna have quite a big discussion as to what "x server" means. x11? twitter?
"guys x servers are down!" \
"have you checked your .xinitrc? did you start x?" \
"whats an x innit racecar? the x servers are down!" \
"how do you use x without knowing what an .xinitrc is... oh"
meanwhile reddit gonna rename themselves to "wayland"
TP