Wow, you've said a lot in just a few words! First off, welcome to you and I'm glad you found your way here! Yeah! Hope you stay around and see how wonderful it is here on the forums. You will find a lot of support.
Then, you need to ask yourself, "how can who I am be the biggest mistake?" It's not a mistake, you are who you are. God created you gay and if it was a problem, you wouldn't have been created gay. Period.
That's a challenge to get through tho! Well, there are many here who will be happy to discuss it with you. And will certainly be encouraging and supportive. Being out to a few is a start. It sounds like you have a supportive group which is important when you are coming out.
I was afraid at first, but when I realized that being myself and living out was quite wonderful, and that there was no indication that God was horrified at it (in fact the opposite is quite true - I'm so very blessed!), it's been nothing short of awesome and I wouldn't change a thing! (Well, maybe just to have accepted myself and come out sooner!).
Welcome & so glad you are here!