Oil pan

Okay, so I used to do a pretty okay job at changing the oil. Someone once told me that I can change the oil just by taking out my filter letting it drain out and putting a new one on. Due to family issues I got distracted for months and I did not change my oil. One day at three in the morning I was on the freeway and I decided to race some guy and that is when I noticed that my car's tachometer started bouncing back and forth so I exited the freeway and my car shut off. Luckily there was a really cool guy with a tow truck at the gas station that I was at and he towed my car for free. He looked at it and he is not a mechanic, but he said he knows a bit. He saw that around my oil pan on the bolt it was leaking and even a little around my filter. So once I got home I waited to the morning and I took off the bolt that I had no idea existed and bang so much thick black oil started just coming out. And that is because before that I apparently "changed" my oil only putting roughly two quirts. Now the problem that happens is that my engine keeps shutting off it and it makes a loud kind of knocking noise. And I just want to know if you think it is my whole oil pan or just because I never properly changed my oil?