Check out Timeshare Users Group that has a wealth of advice from owners. Here's a link to the Marriott forum: https://tugbbs.com/forums/forums/mar...lub-abound.29/
Check out the "sticky" threads at the top of the list for how to weigh the factors about purchasing and using the system. In a word, the typical advice in your situation is rescind the purchase (if you're still in the window to do so) and research your options.