Obviously coming out is different to everyone, but I found that different situations meant that I was "coming out" multiple times. So what I mean by this is that whilst I told my close friend group and felt relieved because I was able to be more "myself" around them, I also came out to my parents, and work colleagues on separate occasions.
I'd say that in 99% of situations, it's better for your mental health, but it also isn't for everyone as well. My personal experience was that I didn't feel like I could come out to my parents until I was independently away from home with a solid car and a job for fear of being kicked out and disowned like all the horror stories you hear of. That's certainly far from what happened, but sometimes you just hype yourself up that way and it was a huge relief lifted off my shoulders after feeling like I had been hiding my true self.
I also adopted a strategy early on that I wouldn't hide and if anyone asked if I was gay, I'd tell them straight up and not dodge the question, but if they asked if I had a girlfriend, I wouldn't make excuses or anything, just say no, and if people pressed and asked why, tell them straight up I liked guys. It was much better than hiding and dodging and less tiring trying to fake a smile when someone would say "no worries, mate, you'll meet the right woman soon".
There was a running joke at work for a little while when I was in a relationship and my work colleagues noticed my mood lifted and they kept asking me, so who's the lucky girl, and I'd just joke and say "Me!". Because I was playing coy they termed me "under new management" and were very surprised when I introduced my then "boyfriend" as "new management" 🤣 We all had a good laugh and life rolled on because everyone through i was straight and it became an in-joke for others that didn't know in the building that didn't work in the team I was in.