Most of this is YA but, they don't revolve around coming out:
I'd love to recommend Arrival by Chris O'Guinn, but I don't think that one is feasible, the series was cancelled and the ebook pulled from Amazon etc. by the author because it didn't sell well enough and he didn't want people investing in something he wasn't going to continue. If you're lucky maybe you can find one of the paperbacks though. Wish I'd picked one up when I could have. It was good.
I really liked Into This River I Drown by TJ Klune, I particularly recommend the audio book because the narrator is what really sold me on it.
I loved The Foxhole Court series by Nora Sakavic, the first book is free on Amazon and the next two books are only 99¢ each. Worth way more imo, so great. May require trigger warnings though, the second book in particular. There is also a romance, but it's super slow burn, like not until the third book slow.
Last Night I Sang to the Monster by Benjamin Alire Saenz is fantastic. Also calls for trigger warnings. The character in this however isn't explicitly gay. It's fairly obvious though that that's something that he'll have to address later in his life. This book however came out before the author himself had even officially come out. It's mentioned about his later book Aristotle and Dante Discover the Secrets of the Universe that he was scared of writing the book (AaDDtSotU) and almost didn't because it felt like coming out for him, or something to that effect. So I don't think he was ready to make it a stated fact that the character was gay. But again it's fairly obvious.
You could try The Screwed Up Life of Charlie the Second by Drew Ferguson,
Sweet Tooth: A Memoir by Tim Anderson which was another book the audio book sold me on,
Wings of Equity by Sean Kennedy,
Grasshopper Jungle by Andrew Smith,
More Than This by Patrick Ness,
Imaginary by Jamie Sullivan,
This Is Not A Love Story by Suki Fleet,
Almost Like Being in Love by Steve Kluger, etc.