07 L322 4.2L SC sudden engine issues and oil

Hi all! Forgive me for the novel I’m about to write. Whew, here we go. **KEEP IN MIND: I have been anal about maintaining and repairing any/everything per LR/manual specifications **
I Was driving home and he engine was noticeably hesitant and “sputtering”almost as if it wanted to stall. I thought it was perhaps dirty spark plugs, however not 20 sec later, Engine light(amber) started flashing, with “reduced engine performance”. I was “creeping” to the parking lot right next to me, and engine stalled while driving. Instinctively I went to recrank,which it did, but stalled out again. I was able to re crank a second time and coast into parking lot. I immediately plugged my basic engine obd2 in, and got random misfires on all cylinders. P0300-p0308. The only codes I had prior to this incident were p0171 and p0174(running lean), however I had cleaned maf and changed air filter, and hadn’t gotten those codes again. I had truck towed home, and a mobile mechanic came to “diagnose” it. He is able to crank it right up and it doesn’t stall out for the 15 min it’s running, but it was running rough. Sounded like A “heavy Chevy” and was shaking. He never did give me the codes and diagnostics bc he said he’d have to research further. (That wasn’t going to work for me) I let it sit without cranking for a cpl weeks, and when I went to crank it, the battery(less than a yr old) was completely drained. I jumped it but it was shaking violently and barely made it to the other side of driveway before stalling out. I removed battery terminals and have checked all fuses, relays, cleaned intake & hose(connected to maf),repaired muffler and rear pipe leaks, but couldn’t find any other exhaust coolant or intake leaks. I did notice there was a small puddle of oil inside the intake manifold. I haven’t gotten it out yet, bc im not sure if it’s supposed to be there or not. I know that I need to change plugs and prob coils, but I can’t keep the truck running long enough to figure that or anything else out. I switched relays around to see if I might need a new fuel relay, jumped it and it shook and stalled right out. I even tried to give it some gas to keep it running and it felt like there was almost no response to the accelerator pedal. NOW, I have oil seeping out of every seal, bolt, crease/side, pcv, the bottom of where you pour oil into, the top of oil dip stick and around all he coils/plugs(both sides)no oil is dripping onto driveway, but it’s def seeping out from every pet of head. No fluid levels are low, oil isn’t milky, and I’m at a loss. Going to check the fuel filter and pump but any suggestions would be greatly appreciated. I’m so fed up with 1 step forward and 3 steps back.