Oh Honey, I am very sorry for you. I know that can be exhausting to get up before 6am constantly. But it will pass, earlier or later.
And now regarding her sleep. You did have EMW when started this thread but they were for sure UT (too much day sleep, 3 naps, 3h+ daytime sleep). Now you have a different story Hon, as she is OT. So maybe it's worth to try EBT on days she didn't sleep much or had 1 nap day. I am not promising it will solve all your problems, but it's worth trying if she is a kiddo who is catching up on lost sleep.
Reading your post and looking for a starting point... From 3 naps you went to one on some days.
During this time she was taking 2 naps (45 minutes) and one longer nap (2 hours) during the day.
From sleeping 10.5-11h at night and 3.5h during day (around 14h per 24h), now she is getting 8-9h according to what you wrote.
That's why I would think of:
1. Trying tomake sure she is getting 2 naps a day... everyday for now. I remember my DS when 10mo and really he needed couple of days on 2 naps to recover after one day on one nap. If you are mixing days with 2 and 1 nap, it will be difficult to catch up for her. Aim for 13.5h total sleep per 24h as she was getting 14h quite recently and it was fine for her.
2. 13.5-14h per 24h means that if she did 2 naps (total 2h) aim for 12h day as a maximum. If she did more like 2.5 or 3h, than you can work on a longer day.
3. One nap days at that age are very risky in my opinion as they can sleep 2h per day and still be very OT after 12h day as too long shots of A is really a challenge for them. So if you just have a day with 2h nap (only one however) I would aim for even shorter day than 12h like 11.5. Even if she wakes at 5:30/6:00 next day, she should have better night and be able to survive next day.
What do you think Honey?