Sorry, I know this day has haunted you since you began posting. Now that it has come and gone, you COULD try to focus on the REST of the world, especially you sister/friend and all the fun, non-sitch things you could do together. Maybe to ease your conscious, you could admit to them that you are having problems with H but not admit to all of it. I don't know if that makes it easier or harder for you. I would hate to advocate lying to sis, but then again, we all know that much of the time family & friends do little to help and some to hurt. It may just have to be a judgment call when the time comes.
For me, it would depend on how I thought these people would react and IF they would be receptive to me explaining DB to them. I know in my case, my family would NOT be very accepting of the sitch and it would put tremendous strain on my marriage (by way of open disdain for W), if they knew the truth. If there were some way you could just totally GAL during this time and focus on you and your visitors, I think you would have an ok time of it. Just make sure you DO what you think is right and then stick by that decision. There is NO right and wrong way to do this, only the way you decide is best, and hopefully that decision is made free from extreme emotion or fear.