Coming Out Support Group
This community is dedicated to the challenges that gay men and lesbian women face, both between the partners in a relationship and from other influences (family, society, etc.). Find support and talk to others who may be facing the same challenges, and share your experience.
I feel like if they were real friends that they would accept you for who you are and not what they want you to be.
However, your reaction, although understandable, is not constructive. The picture you paint is one where you discovered the betrayal and steamrolled all involved. While a confrontation is justifiable, there are ways to do so constructively.
First up is Eva. While she is guilty of gossiping, you shouldn't be too hard on her. I doubt she knew it was a secret. In the future instead of demanding to know things from people, try framing it in a way that conveys the gravity of your need without hurting someone relatively innocent in the matter. For example, you could say "Eva, can you please tell me where you heard that? True or not, it bothers me that information is being spread about me that should be private. I appreciate you telling me and for my own well being, I'd appreciate it if you told me who exactly told you this." See? Still firm, and not combative.
As for Lain, well he is definitely less innocent than Eva, but still not truly the bad guy as both he and Eva probably didn't know to keep it secret. Often when things become gossip, the disclaimer that it is strictly confidential gets tossed out. Again, keeping your composure and not being "utterly pissed off" would have been more effective. When he came up to you again however, he was wrong to assume he automatically deserved absolution. A good response to this would have been "I appreciate your apology, I truly do. However, what you said about me was deeply personal and it was severely hurtful that you would spread such a thing about me. While I know you are sorry, I still need time to process things, so please understand that I am just not able to give the response you want just yet".
The one who truly and intentionally hurt you is Hay. She decided that gossip about you was okay to be leveraged to gain the attention of her crush. This is wrong and I'm sure you both realize it. Unfortunately some people tend to confuse accidents with regrets. She didn't accidentally tell that you were bi, but she does regret it. She screwed up, and she knows it. To cement to her just how much that hurt you, don't write her off, don't ignore her, don't retaliate, instead say "Hay, you know you are my friend and you know I love you, but I told you something deeply personal looking for the support of my friend and you spread what I told you in confidence. I understand you regret it and I don't believe you would intentionally hurt me, but please understand that I now feel hurt and I am unsure just how much trust I can place in you. That hurts just as much as you sharing my secret".
I agree ignoring the issue is bad, and I can sense that you are a person who likes to confront her problems, so I've offered advice that is a bit more forward than I usually would. The most important thing to remember is to frame your confrontations in how the actions of your friends made you feel. Like, "When you told Lain my secret, it made me feel...". Also, feel free to tell Eva, Lain, Hay and anyone else that this is your experience and your journey and it is your decision when you come out. Coming out is a deeply personal experience that others shouldn't force, and spreading gossip does that. Ask them to please respect your privacy. If they truly want to be your friend, they will encourage you going forward.
This ultimately will be a big learning experience for you; one of vulnerability and hopefully empathy. People are complex. Eva, Lain and Hay aren't bad people they just made bad judgment calls. Sometimes being the bigger person isn't making sure those who mess up are punished, but it is helping them see that actions have consequences and can hurt the ones they care about.
Tread lightly and please try to focus on the good, it will help temper your anger into something constructive.
This is the kind of thing you are going to face your entire life, learn to trust your instincts, if something tells you not to trust someone then don't, no matter how close you are. Don't be afraid to trust people in general, but be careful doing so.