[ramsa4200]

i have a 90 celica
just recently my check oil light comes on, i am a newb when it comes to cars and ask my friend who says "you just need an oil change".... much to my surprise after two days of driving with the light on my car starts making a pretty loud clicking noise (like when you roll your tongue) and i found it makes the noise louder when accelerating and when it finally made a screech noise i pulled over and called for help. so i pull over have my friends dad look at it and we find out that i have almost no oil... so he hooks me up with some nice thick oil hoping that giving the car some oil will stop the noise... the noise didnt stop but it did become less loud only when accelerating past 3000 to 3500 rpms is when the noise becomes really apparent. now my friends dad who helped me out works on cars and told me that the engine is hurt but he didnt tell me what was hurt about it... and i cant go to a mechanic because lack of funds. now i am afraid to drive it because i was told that riding with little oil could have screwed my rods or pistons up and since i only know the basics of cars i cant tell you anymore than that. i assume its pretty serious and any information on what might be causing the clicking noise will be very helpful.
i feel like a complete jackass because some not getting my oil looked at could of prevented this whole thing but instead i am searching for answer trying to find away out, anything suggested will be greatly appreciated... thanks.