There is a new paper on this topic, here is the abstract:
This article provides recent estimates of earnings and mental health for sexual and gender minority young adults in the United States. Using data from a nationally representative sample of bachelor’s degree recipients, I find a significant earnings and mental health gap between self-identified LGBTQ+ and comparable heterosexual cisgender graduates. On average, sexual and gender minorities experience 22% lower earnings ten years after graduation. About half of this gap can be attributed to LGBTQ+ graduates being less likely to complete a high-paying major and work in a high-paying occupation (e.g., STEM and business). In addition, LGBTQ+ graduates are more than twice more likely to report having a mental illness. I then analyze the role of sexual orientation concealment and find a more pronounced earnings and mental health gap for closeted graduates.
That is from Marc Folch at the University of Chicago.