Background: The early postpartum period brings significant psychosocial changes. While breastfeeding difficulties can increase maternal emotional burden, social support may protect against postpartum distress. Objective: This study examined associations between breastfeeding difficulties, perceived social support, and baby blues symptoms among mothers in Croatia. Methods: A cross-sectional online survey was conducted among 1,378 women (≥18 years) who delivered within the previous year. The questionnaire assessed obstetric data, breastfeeding challenges, social support, and early postpartum emotional symptoms. Data were analyzed using descriptive and inferential statistics. Results: Breastfeeding difficulties within the first 14 days postpartum affected 79.3% of mothers, frequently involving sore nipples (25.7%) and latch problems (25.6%). Mothers experiencing breastfeeding difficulties reported significantly higher baby blues scores than those without (M = 3.28 vs. M = 2.72; p < 0.001). Furthermore, the emotional burden of breastfeeding positively correlated with baby blues intensity (r = 0.344, p < 0.001), whereas perceived social support had a protective, negative correlation (r = -0.263, p < 0.001). Regression analysis demonstrated that social support significantly mitigates the negative impact of breastfeeding difficulties on maternal emotional wellbeing (p = 0.033). Conclusions: Breastfeeding challenges exacerbate baby blues symptoms, but adequate social support buffers this negative effect. Early identification of feeding difficulties and proactive professional assistance are crucial for improving postpartum mental health.