The first-year post-diagnosis is the most challenging and stressful period in the lifetime of a young child and adolescent living with diabetes, given the adjustments that are meant to be adopted. Therefore, psychosocial factors affecting newly diagnosed children and adolescents need to be well understood and children supported to improve treatment adherence. However, evidence concerning psychosocial experiences among young patients with diabetes is scant in Uganda. This study explores the perceptions and experiences of newly diagnosed children and adolescents in Uganda. A qualitative exploratory design was employed. We recruited participants aged 6 to <18 years diagnosed within twelve months from three study sites: Mulago National Referral Hospital, Wakiso HCIV, and St Francis Nsambya Hospital. Twenty in-depth interviews were conducted, and textual data were analysed thematically using a framework approach. We identified five themes: battling with symptoms, emotions at diagnosis, challenges in coping with diabetes management, changes I have made, and positive outcomes registered. The analysis found that young people living with diabetes experience a new world of adjustments, including insulin therapy, routine blood glucose monitoring, and dietary changes that are often difficult to deal with, especially in the first year after diagnosis. Continuous psychosocial support to newly diagnosed young children and adolescents with T1DM is vital. Addressing psychosocial challenges may improve adherence to treatment regimens. Our findings have demonstrated the mixed experiences of newly diagnosed young children and adolescents living with diabetes, from anxiety and stigmatization to independence.