28 Days(2000)

Gwen (Sandra Bullock) is sent to an addiction rehab facility after stealing her sister’s wedding limo and crashing it into a house while drunk.  Her boyfriend Jasper (Dominic West) sneaks her prescription pain killers in her first few days in rehab and Gwen throws them outside, but then later tries to retrieve them and almost breaks her leg doing so.

Gwen realizes then that she really needs help and starts to work on her issues, including coming to terms with her mother’s death by an accidental overdose when she and her sister were very young. 

After 28 days, Gwen is clean and leaves rehab.  Initially Jasper pledges to get clean to support her but quickly falls back into his addiction and so she dumps him.