Hi Patty, welcome to the forum. This is a great place filled with wonderful, supportive people, I really hope you like it here.
(((( hugs ))) I am so sorry you are having such a hard time right now. Unfortunately stress is one thing that does not go well with lupus but it's the hardest thing to avoid. We all have stressful moments in our lives, we just have to deal with it the best we can. Guilt I think is the hardest, but Lynnwood is right you have to realize you are doing the best you can and don't beat yourself up (I know it's hard). Take a nice hot bath, drink some hot tea and take good care of yourself and get better so you can see your dad.
It sounds like you have a wonderful family and offer great support to your sister and nephews, just keep doing that and I think it will get easier for you. We're so lucky this day and time, we have the internet, cell phones, etc so it's easier to keep in touch with our loved ones. Maybe you should get a webcam for you and your sis that way you can "see" your precious nephews and they can "see" you when ya'll talk! I don't know sweetie, I'm just throwing out ideas here, I know your heart is broken and I will be praying for you and your family. Take good care of yourself and keep us posted on how things are going.