Phone stuck in sideload mode

I am trying to flash stock rom with magdisk, and after executing ./adb reboot sideload, i tried ./adb sideload file.zip. however, it showed

adb: sideload connection failed: no devices/emulators found
adb: trying pre-KitKat sideload method...
adb: pre-KitKat sideload connection failed: no devices/emulators found

now, I cannot get into regular boot. after hard resetting(holding all buttons), it just reboots... into sideload mode. I tried waiting a day, but nothing happend. I have a samsung galaxy a14. SM-A145R, with EUX region code.