The mental health of individuals identifying as a sexual minority faces greater risk and vulnerability compared to the heterosexual population. Although individuals from these groups are more likely to seek support from mental health services, they experience poorer outcomes and are less likely to re-access them. This is highly indicative of mental health needs for this population not currently being fully met by services. This thesis explores the role of minority stress in sexual minority populations in health settings, as well as factors influencing the sharing process of sexuality in psychological therapies. Part A involves a quantitative study examining the relationship between minority stressors, demographics, and wellbeing among sexual minority individuals. In particular, we focused on minority stressors including rejection sensitivity, internalised stigma, and experiences of discrimination. Findings indicate that rejection sensitivity, internalised stigma, younger age, and non-binary genders predict anxiety. Part B entails a qualitative reflexive thematic analysis of experiences shared by people identifying as a sexual minority, who have accessed services, and factors that influenced the sharing or not sharing of their sexuality. Findings indicate both systemic and interpersonal factors impact whether sexual minorities share their sexuality with their therapists or not. Moreover, intersectionality and relational factors emerged as novel factors that impacted sharing. Both parts of this thesis consider the voices of people with lived experiences to provide insights to consider in healthcare practices, for the improvement of care provided for individuals identifying as a sexual minority.