I am trying to figure out what I need to repair next?

3yrs ago My car went into "limp mode." After many do it yourself attemps my husband and I figured out it was the ignition coil. After replacing it w/an aftermarket part we spoke to a mechanic who reccomended the use of original equipped parts from the dealer. We did and it fixed all issues. Now while driving around 40mph the check engine light started to blink and I lost driving power and it sputtered terribly. My husband is away fighting this war for another country and I'm on my own trying to get this fixed. I went to an Auto body shop recommended by friends and after pointing out the ignition coil was cracked I gave him the go ahead to fix it. $220 later it still runs the same and he says the connector wire broke apart and fell onto the engine block and shorted out the computer. He said I need a new computer but he is not going to do the work. Unsatisfied and feeling like the shop might have done something wrong. I went to a neighbor to help. He then reminded me my husband had to replace the ignition coil before using the part from the dealer, realizing the part from the shop was aftermarket. My neighbor changed it for me and it still runs the same. I went to Autozone to have a diagnostic scan it it read igniton coil and misfire. So I had him change the spark plugs and the igniton coil connector which the mechanic said he fixed by putting electrical tape all over it. After removing the tape we saw exposed wires and they weren't seperated so he fixed that as well. We were sure this would fix the issue. NOPE. So I did some research and found out how I could use my run, off process the view the codes. It read P-300, which is misfires detected in multiplecylinders and P-351, coil#1 not reaching peak current during right time. So he changed the plug wires. It runs slightly better. I did code check again and it only reads P-351 how to I fix this and could my PCM really be bad? I'm just not sure if it is the PCM. How does my car erase codes and everything else be fine. If the computer is shot! Please help!