I hope that you get more replies to your post from others, but in the interim—what country do you live in? Maybe I can help find you some support.
S.
Seek a support group or counselor in your area. You have to be comfortable with who you are before you come out. But hiding it forever will only make you miserable and make you miss out. Once you're out, you're out. It might be a struggle at all sorts of different times, encountering prejudice and such, but if you are comfortable in your skin you will be okay with that. If your mom's approval means a lot to you, you should work on being comfortable so you can tell her. Maybe start by suggesting at it vaguely so she isn't taken too off-guard and surprised. But your mother will still love you, even if she doesn't take the news well.
Also, just wanted to say that in my country and in my eyes, and in what I fully believe is true: You are not a sinner. You are doing no wrong. Everyone is created equal, and some are created gay. That shouldn't be a thing or an issue at all. Being gay shouldn't even really be a phrase, you're a human being, just like everybody else. You're just being a human being that is interested in the same gender as your own. I see nothing wrong with that. Don't be so down on yourself about it. Learn to accept yourself. Being gay is just as okay as being straight. And I'm sorry you had to grow up in a place where that isn't the mindset.
Best of luck!