Welcome to planDisney, Gemma.
Oh, bother! I'm sorry that you've had trouble making Theme Park reservations. I wish I had better news for you, Gemma. However, at this time, making these reservations is essential to entering the Theme Parks (even with a valid ticket). It's certainly possible that other Guests might change their plans and cancel their reservations. Therefore, I'd encourage you to keep checking to see if anything opens up.
If you manage to grab a last-minute reservation to any one of the Theme Parks, then you'll be able to use your
Park Hopper Option to visit another park of your choice after 2:00 PM.
The great thing about unused
Walt Disney World tickets is that you can always use them on a future trip. Even if they expire, the value of any unused tickets can be applied to new tickets (you'll just have to pay any difference in price). Just make sure you check the
Theme Park Reservation Availability calendar before you make any concrete plans.
As Dory says, "When life gets you down, you know what you gotta do? Just keep swimming." I hope everything works out, Gemma.
Mike