Shut off while driving and will not start

I recently purchased the vehicle listed above. When buying everything ran fine, it would take about 10 seconds to crank up, but I chalked that up to a bad fuel pump. About a week ago it shut off while driving, when running tests, it seemed as if the alternator was bad. I replaced the alternator with a 2011 Crown Victoria alternator since I know they produce a higher voltage and it started but eventually shut off again. Gave up for the day and came back the next morning to try again, car decided it wouldn't even crank over so I tried forcing the starter by using a screwdriver to connect the power post to the relay post and it just whirred. Opted to replace the starter and it allowed the car to start one more time and it shut off again. Checked the IACV and it was basically seized and completely full of carbon and debris, so I swapped that as well as cleaning the MAF. After that the car refused to crank, tested battery at 13.6v and was confused so since the new starter had lifetime warranty, I just did the screwdriver trick again and it still didn't start. Tested fuel pressure on the fuel rail and it was only at 5 PSI. So again, instead of doing the fuel pump I opted to swap fuel filter, which was horrendously bad, and after swapping it the fuel pressure got up to 40 PSI, but quickly dropped after. Still assuming bad fuel pump check valve on that one but couldn't be bothered to drop fuel tank yet. After doing all this it still didn't crank, and I found the battery was drained. Tried jumping the car and just letting it charge for a while and still nothing. Eventually once the battery was at 13v again I left it for about an hour to try and check for a parasitic draw on it and found that it was being drained by like 10+ amps which I thought was insane. Nearly burnt my multimeter leads just by touching it for a few seconds. Pulled fuses one by one and never saw a drop so I opted to pull them all at once and still no drop. Drained the battery rather quickly and it entirely refuses to even try to crank over. I'm a tad bit in over my head on the electrical side now and wanted to see if there was any advice for me or anything I should try to do next. Next thing I'll try is probably disconnecting the starter and seeing if the draw goes away, assuming it might be the relay cable just got fried and is resting on the frame somewhere just drawing you but shouldn't removing the relay prevent that? Any help whatsoever would be greatly appreciated.