This probably is not a gay movie 100%, but it is very interesting and I recommend it.
And the band played on is a 1993 American television film docudrama about the discovery of the AIDS epidemic, and the political infighting of the scientific community hampering the early fight with it. With Matthew Modine, Alan Alda, Phil Collins, Richard Gere, Anjelica Houston, Steve Martin, BD Wong, Ian McKellen.
https://www.youtube.com/watch?v=O38zYpzqdZg