Okay, I'm probably going to keep this short and sweet probably, but let's just see it that actually happens.

So my coming out was about two maybe three months ago, yeah no very long ago. It also, unfortunately, wasn't on my terms...

At the moment I was having some seriously sexuality confusion, so I thought I was full on lesbian at the time, I was also dating a boy. I told my sister that I was a lesbian and was going to break up with this boy today. (Now you see before we started dating he actually didn't want to at first, because he was going through some serious depression at the moment, so in case him and I broke up he didn't want that to be the final thing to send him off the edge.)
My sister had put this into concern, and I had not... So when my sister said "what if it causes him to kill himself?' it sounded to me that she was guilt tripping me. So when we got to school (we were walking) I was holding back tears, because if anyone killed themselves because of me that would just completely destroy me, so had my best friend come outside with me so I could talk to her about it. By this time I was crying really hard as I explained what happened between my sister and I. (also on that walk the told me she didn't believe I was actually a full lesbian) So later in the day I broke up with him like I was planning on, I told him the truth as to why. He completely understood, and said everything was cool between us.

Now you know how highschools are, so apparently around last period people knew what happened between my sister and I, thankfully not the whole school though. So my sister and I didn't walk home together, and she got home before me.... I get home, and my sister is sitting on the couch, crying... Then my parents asked me what happened... I was terrified of them finding out my sexuality wasn't straight, I avoided that as much as I could, just talking about how I broke up with my boyfriend. Then it happened... My mom asked me, why people though my sister was homophobic. (she's not by the why, she's awesome) Anyways, I lost it, I just broke down crying, and yelled at my sister "Wow you're such a wonderful sister!" and I tried to storm off, but my mom didn't let me... I told her I didn't tell anyone that my sister hated gays, but apparently that's what people thought...
Lucky for me, my parents actually accepted me, and said it was okay.... I still wish my coming out was on my own terms though...
Also my parents do know that I like boys and girls, but they don't know I'm pansexual, I don't even know if they know what pansexual is.

Anywho, I guess moral of the story. When it comes down to it family is all you have in the end, so stick together, and try to make sure you're able to come out on your time. Don't try to force yourself to be ready, and don't have someone else tell your parents before you're actually ready. However do not stay in the closet forever, it eventually get's better once you're out.