handed civil theft notice from employer and signed promisossry letter. no arrest or police were involved. very scared. what will happen

I was caught purchasing items for a manger where items were scanned 4 a lower price then what it really was. she told me 2 add things for myself & wasn't aware of this until I got 2 the register but still went through with it cause I was scared. I was very uncomfortable and wasn't sure if I should say something because I still looked bad on camera. I was still accused since I went through with it and didn't say anything and since a few items were for me. I signed a promissory note to pay everything back. I was handed a paper that says civil theft notice and their attorney will be contacting be about the claim. There were no police involved and was told that they will b going over it with HR n my manager 2 whether I can come back to work. I'm very nervous and so scared whats going to happen