possible job interview

i got a call yesterday about it and called back and left a message..they want me to go in on tuesday and interview..and i dont know..im happy but not at the same time..if i do interview and get the job ill have to leave my cls i work with now adn that makes me feel so guilty..but i also have to realize that im just not making enough to live on right now..im not making enough to keep gas in my car or to even save up to move out and its getting harder and harder and the bills just keep coming...my job isnt very stable at all..my cls lose hours and have been losing hours since before the summer started..im getting more hours now but im also being stretched pretty far and working with 5 different cls throughout the week..i make 4 different pay rates all within one check..and yes i feel guilty about it but i know if i get the job ill have to say goodbye to my job now..because ive been working with them for almost 9 months and i havent even hit the $10000 for gross to date..cas i checked my check last night..thats not enough at all to do anything with...so guess im doing the right thing..i think..i hope..ill just have to figure out how to say goodbye to my cls when the time comes