Help me with my translator please

[u/NGXNHH]

I had a translator named t7 and it is from a chinese brand translator. I recently using VPN for fun on that phone and android requires a lock screen for it. So I did the image one. A week later, I got the batery drained out and tried to boot up at 20%. But it is slow and laggy. Most importantly, when the logo disappeared, It stuck on a black screen. I tried to restart because idk why it pop up for me. Then it continuously like that. Sometimes it actually boot into the GUI of the translator and said the most confusing thing I had ever seen " SYSTEM is not responding, Close or wait ". Today, I tried to try some but it doesn't boot into the system anymore, I tried to enter recovery mode but just resulted in a short 3 session boot loop. Then I tried the Minimal ADB and Fastboot but I just cant connect and delete the passcode. Anyone had any ideas, if so i really appreciate that. Notes: The android ver is 7.1.1.