Stop stressing yourself out....I know easy for me to say. But its true and everyone said it to me. My advice is to wait until after the Disney trip. Go on the Disney trip, have a fun time and enjoy not having to make a million potty trips. So, she can't use the pool, that is something you can tell her when your there. No, sorry honey you have to be a big girl that uses the potty to go in this pool. And find other things to do, which I am sure there is tons of other things to do.
Then after the trip decide your next plan of action. I like others agree that taking away all diapers is your next step. Yes, there will be accidents, possibly lots of accidents, but that's potty training. Also, when you decide to go forth and she screams about sitting on the potty, tell a story to her, read a book, make her sit on the potty until she goes. Then when she goes, celebrate! She will soon learn the potty is not scary. But know this might take a little while and it will take patience and possibly lots of cleaners.
Trust, me I've been there! I tell people all the time that potty training was the hardest most frustrating thing I've ever had to do in my entire life...so far. My oldest was 3 1/2 years old before she was potty trained, by the time she turned 4 and started preschool, no one would have ever guessed that only 6 short months prior I had potty trained her. And like you sound, I was at my wits end. I was so over it. I tried everything and anything. I admit I finally resorted to punishment, because it was the only thing left. When we went out to stores or McDonalds, she would tell me she had to go and never had one accident. That's when I knew she knew how to hold her potty, so one day I decided to take away a movie every time she had an accident at home. Well it only took 6 movies and she was potty trained. (I only suggest punishment to other parents when they know their children are capable of knowing the signs.) Now, when it was time for my youngest I dreaded potty training, she was already 1 1/2 by the time I had potty trained my oldest and I was in no hurry to potty train her. I decided to just let her come to me when she was ready. It was pretty relaxing, until, I started to believe this would never happen, she was just about to turn 3 and like your daughter wouldn't even sit on the potty, said she was scared of it. I finally one day decided to go for it sat her on it, while she screamed...waited it out while I read books and she went. We celebrated. I took all diapers away. The first couple days there were accidents, but can you believe by the third day she was telling me she needed to go...and from that day forward she was potty trained. It was a piece of cake! I am telling you all this because I've been there, and I've learned stressing myself out is not worth it, because like everyone says when they are ready they will go and boy are they right. Good luck!