Kim,
The girls will realize like all of us do (when they are adults) what a great mom you are! I really can't provide any clear ideas about how to reduce stress for you and your girls. But, I can say that YOU ROCK for doing the right thing! Of course,I would enlist any family members to assist if possible.
Maybe you could put your girls on a reward system of sorts. That way, on Sundays you can review all the good things they did and praise them with something special. Like cooking a favorite meal or baked treat upon reaching so many points collectively. And maybe the daughter that got the most points gets to plan a picnic or pick a movie rental. That way, it is give and take, they work and get reward, and maybe the fussying will be reduced and replaced with reward and praise.
I had to find a way to reduce stress in my house with my kids. The reward chart help me turn fussying into a proactive way to praise my kids for their accomplisments. It is working pretty good. Although, they are still kids and I still have my fussy moments!!
If you think this is something that might help you, I'll be more that happy to send you my reward charts for my kids. They are made individual for each child so they can accomplish things they are capable of.
Bless your heart! Pray for guidance... One day your girls will understand and they will say thanks!