Code P0301 cannot clear it

To start, I got this car not running due to a bad head, first I tried to cheat by pulling head from pick and pull this. Allowed me to move the car it went sour overheated took original. Head had it repaired did not want to do it again so I paid a shop $1,700.00 to remove and replace another. Bad move shop did lousy job took the car home it was over heating added some k seal in radiator corrected the over heating. AC not working attempted repair found it had bad AC lines remove and replaced AC. Works, then a little later mil light on p0301 replaced. Plugs and wires no change a strange thing happened mind you some weeks had passed while I researched information on this thing I replaced the IAC the MAP sensor replaced the coil I could not control my idle rpm's. Put old coil back all good that was the first strange thing then I did a compression test either I did it wrong or I have low readings across the board not one exceeded 70 lbs. Put it back together car has power good pick up remove and replaced cam sensor, code still exist. I am too far in to let go now. Bought car for $500.00 paid $1,700.00 for head remove and replaced, countless hours and parts, I am at least $2,000.00 under this thing and lost. I read forms watched videos scanned I have no idea but take it back to shop, it has been bout eight months. Thanks