I'm so *tired* of this...

Warning: mom on the verge of insanity ahead. If you have never been a mom on the verge of insanity, do not have kids, or do not want to read about mine, proceed at your own risk.

Both of my kids are crying in their beds right now.
That would not be so unusual if it was perhaps the start of naptime on a day in which we had maybe a long morning. But as I sit here, it is almost 3 o'clock in the afternoon -after our usual naptime- and they are both in their beds crying, having had no nap as of yet.
Here's the scoop. Savannah has had a rough couple of days. She's been awakened pretty early each morning by Sawyer, being not so considerate of the rest of our sleeping schedules, in his room by about 5am. And it's wearing on her. I can tell she's super tired and today she has lost it over some very minor things. So on the way home from preschool today I alerted her ahead of time that I really wanted her to get some sleep during her rest time today. (and for the record, she actually agreed with me. at the time)
So we get home and have some lunch and I let them both know we can all play together for about 30 minutes and then we're all going to take naps. So we make it to naptime and I tuck Savannah in her bed and talk to her again about how tired it seems like she is today and how she will feel alot better this afternoon after a good sleep for rest time. We turn on her music and put her books away and get her settled in and I think we're good to go. She's so tired, I think to myself, she'll be asleep in five minutes.
Fast forward to 2:00; (that's the designated time that "rest time" is over and she can come out of her room) I'll skip over boring you with all the monotonous details of how many times I was in there shushing her singing, removing books from her bed, how many times she got up to go potty, etcetera, etcetera. Savannah comes out of her room at 2, having completed her required rest time. We snuggle for minute and I remind her once again of how tired she was this morning and how that makes her grumpy and whiney and not very much fun and I wonder aloud why she didn't take a little nap after all that. She said she felt much happier and her body just wanted to play. I look in her tired little eyes and I tell her that if she can be happy; fine. But if she starts to cry or to whine, that tells me that she's too tired and she will go right back to bed to get some sleep. She agrees. And guess how long it takes before the tears start? About 6 minutes. She was writing "lists" and looking out the front window sitting on the couch with me when she accidentally dropped her water bottle behind the couch.
And it landed on it's side and was spilling.
And that was the end of the world.
She literally fell apart. Before I could reach it, before she could tell me what happened, almost before it even landed I think. So I scooped her up and carried her back to bed. She was screaming and crying "I dropped my water! I want my water! I don't need to sleep! I want my daddy!" In between her hysterics, when she'd pause for a breath, I reminded her of our deal and pointed out how tired her body must be to make her feel so sad and upset and tried to just hug her for a minute, but she was absolutely hysterical. There's just no other word for it. So there she is. And has been for the last almost hour.
Now for Sawyer's part in this. Due to his quickly-becoming-the-norm sleep boycott, I've been keeping him up all morning the past week or so on the days I think he can make it, trying for just one nap a day in an effort to fix this night waking (or early morning) thing. Maybe he's just not that tired(?). So this morning he had no nap, but he fell asleep on the way to pick up Savannah from school, and slept for almost that whole half-hour trip in the car. So I thought that short nap might hold him over a little longer than having to go down right at noon like he usually does for his lone nap. But he was acting very tired anyway by about 12:30. So I lay him down. But for the next almost hour, all he did was play in there. So I actually got him up (which I NEVER do, because I don't want him thinking he gets to decide whether or not it's naptime...) because he seemed to be getting more and more awake in there and so we read some books and then I gave him a bottle and he seemed to be settling down, so I put him back in bed. Which was just in time for Savannah to get up and then start her big meltdown.
So now for this past half-hour, they're both in there crying, and even if one starts quieting down, the other gets louder and upsets the other one again. I went back and forth for awhile trying to get someone to calm down enough to fall asleep, but I gave up and came out here to vent. (can't call anyone... I can hardly hear myself think over the whining contests going on down the hall.)

*Now in the time I've typed this, I did get Sawyer up again. I figured, I could still try to put him down for a quick nap before dinner sometime, but I need to quiet him down because Savannah NEEDS to sleep. So he was out here playing at my feet while I tried to finish typing this and in the span of about 5 minutes, he has fallen and hurt himself three times. Tell me you aren't tired, little man. So I'm holding him and rocking him here on the couch and he looks so sleepy. I take him in his room to rock him in the dark and he starts whining. And then Savannah comes out of her room again.
AAAARRGGHHHHHH!!!

I don't know what the heck happened... I thought we used to have kids actually sleeping during naptime around here. HELP!