1998 Mitsubishi Eclipse engine knock

I have a 1998 mitsubishi eclipse rs ive had it for about 7 months now I did do oil changes reguraly until last recent one I went with out oil for about 2 days and I hear a small knock got louder and louder the next day I turn my car on and drive it around and it gets worse louder then my music I pull over to my friends house and we change the oil and the oil filter and the noise continues to go on can some1 tell me some possiblitys of what this can be?
if I have to resort to rebuilding an engine cause I honestly do not know how to