Accidentally disabled OEM unlock on rooted phone

I accidentally disabled the OEM unlock option on my rooted S7, and am now stuck in bootloop. I can get into download mode but not recovery mode.

I have tried to flash a stock firmware, however odin stops at this point:

<ID:0/007> Added!!

<ID:0/007> Odin engine v(ID:3.1301)..

<ID:0/007> File analysis..

<ID:0/007> Total Binary size: 4089 M

<ID:0/007> SetupConnection..

<ID:0/007> Initialzation..

<ID:0/007> Get PIT for mapping..

<ID:0/007> Firmware update start..

<ID:0/007> NAND Write Start!!

<ID:0/007> SingleDownload.

<ID:0/007> boot.img

<ID:0/007> recovery.img

<ID:0/007> system.img

<ID:0/007> FAIL!

<ID:0/007>

<ID:0/007> Complete(Write) operation failed.

<OSM> All threads completed. (succeed 0 / failed 1)

Is it possible for me to fix my phone, or do I need to buy a new one? if it is possible for me to fix it, how?