Sainsbury's shoplifting

Today I was taken aside by shop security when leaving and they saw me taking meds worth £15 in CCTV. The man only asked me to go back and pay for it at the help desk which I did. I paid and he asked for a copy of my receipt to keep. He didn't take any of my personal details, a photo, make me sign any sort of paperwork or ban me. I left after that so don't know what is going to happen now. I am a uni student really struggling financially and I have multiple diagnosed mental health issues and my anxiety is through the roof. I have never done this before and know how wrong it was of me, but selfishly I'm so scared of what could happen, but I know I am not a bad person. Could anyone give me some advice or does anyone have an idea of how businesses usually deal with this kind of thing? If there could be no berating in replies I would really appreciate it as I know I screwed up and already feel horrible enough about it, thanks