Oh PCM (((hugs))) never feel bad about coming to vent on here, you're right, this is exactly what the talk boards are for, to talk to people who have been through and who are going through the same as you are and therefore understand exactly what you are going through without the words having to be spoken.
To some people getting pregnant is something that comes naturally, they come off the pill and bang, they're pregnant. For people like that it is incomprehensible what it must feel like to come off the pill and then go through cycle after cycle and not automatically falling pregnant. People like that cannot empathise as they have no idea what it feels like, they celebrate their news because they are so happy, and totally unaware of what their joy is doing to those people who are closest to them, and who desperately want the same thing as they already have. Just remember, your baby will come, the right baby, at the right time, the baby you are meant to have. It's something that is incredibly easy to lose sight of when you get that bfn or when af arrives, but when you get that BFP, when you feel that baby kick for the first time, you will know that you were meant to be pregnant at that particular time. And in the meantime we're always here if you need to pour everything out.
As for your sister, she doesn't see you as the enemy, but she's almost in the same position as your friends, but on the other side of the coin. As someone who isn't able to have a baby naturally, to her it is incomprehensible that someone could be trying and getting frustrated when she has to go through cycles of invasive treatments and she knows that there may potentially be no positive result at the end. It will be very hard for her to empathise with you also, because although she knows what it feels like to not be pregnant and to want to be pregnant, for her, the journey is that much more difficult, and for her, she is the only one going through this.
I hope I'm making some sense here.
Just remember that you are never on your own, and just remember that when your best friends are going through their pregnancies and when they're going through labour and the beginnings of sleepless nights, you can be happy for them, and for yourself, because you will still have that to look forward to, and for them, the feelings of being pregnant, the first kick, first scan, will have already passed, and you will still have it to come.
I hope this makes some sense and sorry if this is a bit long, just remember there are others who are thinking of you and who know what you're going through.
keep smiling
(((hugs)))) xxx