Leinster scrum-half Nick McCarthy has said he "contemplated walking away from rugby" as he did not think he could come out as gay while playing the game.
McCarthy talked publicly about his sexuality in an interview with Leinster Rugby website on Monday.
"It affected me so much that I agonised over my future," said McCarthy.
"I came out to my team-mates in January and I was obviously pretty nervous about doing so, but I'm really happy that I did it."
The 27-year-old added: "I struggled with coming out for a while and it was starting to impact on me and my happiness so it was the right decision.
"I only made a quick announcement. But I just remember the room erupting. They were all delighted for me and it was immediately a weight off my shoulders.
"I felt they understood my situation. It's hard to perform at your best when you are carrying something, anything, and that's the same for all the lads. For me it was my sexuality, for others it could be stuff at home, or studies or whatever.
"I'm a private person so I was unsure about coming out publicly."
A host of players from across the sport have been vocal in their support for McCarthy, including his Leinster captain and team-mate Johnny Sexton.
"We talk about looking after our brothers a lot in here and the last few months has been about that, looking out for Nick. And that will continue," Sexton told leinsterrugby.ie
"By speaking openly about his sexuality, Nick will be a role model for others and we couldn't be prouder of him."
Having played for Leinster at under-16 and under-18 level, the Michigan-born player went on to become part of the Irish province's academy set-up and was then given a professional contract for the 2017-18 season.
After helping Leinster achieve success on the domestic and European front, he went on to join Munster, before returning to Leinster for the start of the 2021-22 campaign.
"I spoke to [Leinster coaches] Leo [Cullen] and Stuart [Lancaster] last November and the support that I got from them straight away was unbelievable," McCarthy said.
"They helped and guided me over the months that followed so that I felt more comfortable to come out to the group.
"It's not common for a male athlete to come out in sport, never mind professional rugby, and it's probably something that I didn't want to believe or accept myself either.
"It affected me so much that I agonised over my future and contemplated walking away from rugby altogether because I just didn't think I could come out while playing rugby.
"I needed to accept being gay myself before I could address it with others. I have great friends in rugby but I didn't know how they would take it.
"My experience, since coming out though has been entirely positive. I have realised that anyone who cares about you, just wants you to be happy."
"Around this time last year I started talking to my close friends, and they were very supportive. Those conversations continued as I became more comfortable and accepting of myself.
"In many other professions you may not feel the need to discuss your sexuality. But I felt I wasn't being true to myself."
Fellow Leinster player Jack Dunne publicly came out as bisexual last year, about the same time American football player Carl Nassib announced he was gay. A few months later, Australian soccer player Josh Cavallo made headlines by becoming the first top-flight male footballer to come out as gay.
"Looking at Nassib or Cavallo coming out and Jack here in Leinster and how he spoke publicly last year about his bisexuality, has helped me a lot. I've had good conversations with each of them and they've been hugely encouraging," McCarthy said.
"In turn, I feel if I can now help others come out in professional sport or in their everyday lives and make being gay more normal and not a thing to be worried about, then that is a positive."