This study is testing a new therapy called GRIEF Approach (Grief Recovery with Individualized Evidence-Based Formulation) to help adults who have lost a loved one to a sudden or violent death, such as suicide, homicide, drug overdose, or car crash. Many people who experience this type of loss develop depression, post-traumatic stress, and/or prolonged grief, and current treatments often fail to address all of these symptoms together. GRIEF Approach is a flexible, individualized therapy that combines evidence-based strategies to address traumatic stress, grief, and depression within a single treatment. The primary goal of this study is not to test whether the therapy works, but to evaluate whether it is feasible and acceptable to patients and therapists. Participants will complete mood and symptom questionnaires at the start of the study, weekly during treatment, and one month after treatment ends. Participants will also provide feedback on their experience with the therapy through questionnaires and brief interviews. Findings from this study will be used to refine the treatment and study procedures in preparation for a larger clinical trial.