The simple answer is, you can't. No one will buy it, Wyndham won't issue a transfer of there is a mortgage.
About the only way I know of is to discharge in a bankruptcy. Probably unlikely.
The value in timeshares is in their use. And that has not changed since you saw enough value to buy in the first place. You are in good company, as about half of TUGgers bought our first TS from the developer. So my advice is to join TUG as a member, learn to use it the best you can, buckle down and pay off that high interest debt as soon as possible. Maybe book high demand (holiday) week(s) and rent them to reduce your cash outflow.
Good Luck, and Welcome to TUG!
Jim