We can’t help you much and posting with your real name can hurt you if anyone sees your “change of heart” comment.
Change of heart, by definition = lose earnest money
That is why there IS earnest money. It means “if I change my mind then seller should keep the earnest money for his time and trouble to date”.
We don’t know the contracts, so you have to get someone involved where the house is. Point blank ask the agent and fast, HOW DO I EXERCISE MY LEGAL OUT? Sounds like you are in Oregon and property is in Texas? So that agent has to give you the name of a Texas attorney, not simply say “talk to an attorney”. It won’t help you to talk to one in Oregon.
But do hurry and do something as time is really important on these things. I’d ask the agent AND talk to an attorney, both. Ask her how the HOA Membership is an out and how you exercise that out. She may have a form for it and the timeframe may not have expired yet. You don’t usually get to the day before closing on these HOA type out clauses.
Keep us posted, but do something ASAP.