HELP game error

[jwj31]

i got this game on ps2 and rite after i got to the 2nd island my game started to act weird like i'd be driving into a small town like dillmore or sumthing and there would be no building so i'd stop the car and wait like 10 seconds and they would apare

 

now im on the level called "wu uzi mu" and after the video is done the screen goes black and then after about 30 seconds of waiting it says "error reading san andreas disc"

 

now though its gotten worse to the point that when i turn on the game and its finished loading the screen goes blank then says "error reading san andreas disc" some times it will load normally and i can start to play but the game now frezes so randomly its never the same anymore like ill be driving and it will freze, ill be getting out of my safehouse and it'll freze, and sumtimes ill change the radio from bounce FM to K DST and it will still play bounce FM music?

 

PLZ HELP or im bringing this game back to bestbuy