Macbook Pro Late 2013 Turns off all the time

I Have this MBP Late 2013: https://everymac.com/systems/apple/macbook_pro/specs/macbook-pro-core-i5-2.4-13-late-2013-retina-display-specs.html

For some time now my MBP started restarting by itself since i upgraded to Big Sur; i saw online that it could be an issue with the Thunderbolt port and what not, so i decided to Downgrade to Mojave. The thing is, it just got worse; In Big Sur i could at least use it for some time before it crashed and turned off, now it just turns off in everything:

• Normal Start: It makes the sound that signals it's turning on, shows Apple logo, halfway through the loading part it crashes.
• Safe Mode: Turns on and crashes after logging into my new account.
• Recovery mode: Loads and then crashes 5-10 seconds after that.
• Single User Mode: Loads and crashes after 2-3 Seconds after that.
• Booting from a USB: Same as normal start (bad).

• Diagnostics Utility works correctly, but shows that there is "no problem" with the Hardware on the mac.

IMPORTANT: The thing is when i Downgraded to Mojave, the MBP worked fine for 1-2 Hours before this started happening, I had made a Time Machine Backup in Big Sur to don't lose ALL my info, and i started to recover the info manually (i didn't knew you couldn't get to work Time Machines from Big Sur working to Mojave), and halfway through doing that it just turned off and started doing this. I'm right now in LATAM not even close to a Store that i could take the MBP to (so that's out of the question).

PD: There is nothing connected to the MBP when i turn it on, Resetting SMC and PRAM or whatever does nothing to fix the problem, Internet Recovery (starts and works fine i think), but for some reason after the world logo disappears , it just turns off like all the other methods.