On Thin Ice (2003)

A widow, Patsy McCartle (Diane Keaton), struggles to support herself and her two sons on her meager wages as a waitress. To make matters worse, she ends up losing that job, which at least allowed her to buy her son's asthma medication. Growing increasingly desperate under the strain of debt, Patsy resorts to selling crystal meth for a local drug cartel. She is finally able to provide a decent living for her family, but all of that is threatened when she becomes addicted to her product.