Worried123, sorry to be harsh but you need to get a grip! You need to draw a line under this, the only thing that is punishing you is you. You know you did wrong by condoning your friends behaviour and you are paying the price.
There are two options open to you:
1) write a letter to the store manager explaining your remorse and how you feel and hope that he/she looks on your plea favourably; or
2) Learn by this experience and get on with your life. No one is coming after you, the police have not arrested you, they will not view any CCTV footage in other stores etc...... Basically the sh*t has been scared out of you (and rightly so) but you must look at this objectively, you are paying the price via your consicence, that is enough.
I was caught shoplifting when I was 13yrs, I stole a pencil and was promptly put in a police jeep, taken to the local nick, cautioned and my parents phoned. This scarred me for many years but eventually I got over it. We all make mistakes, thats all part of life, but dont let this one rule yours, learn and move forward. Perhaps also take a closer look at who you associate with.
Best of luck
warpig