I Cannot Help You Fix Your Phone
Samsung always does crap different. They integrated the nasty vertified boot but does not enable fastboot mode which allows disabling it. At least as far my knowledge reaches, your phone is just to me a fancy, glowing paperweight, although I know telling you that is heartbreaking.
Your options could really get up to:
Find, some other posts related, or senior members and developers who are helpful, or Google 'vertified boot Samsung bypass' as a last hope.
Define your A50 as obsolete, (maybe cry for your money then) sell it on ebay as 'parts / unfixable'. If you need the data protected, sell the body, screen, battery and dispose the motherboard in some known environmentally friendly way.
I don't recommend putting your hopes off, so I will provide some related posts from now on.
If you wanna get the data back, there is a (kind of hard) way to do it.
Unsolder your emmc chip and solder it onto a usb drive. Also, replacing the EMMC storage chip may help as the corrupted data will be replaced, and maybe that is the answer of the problem but that requires high soldering skills which puts off most people.