Bought plane ticket via BudgetAir.com. Couldn’t get American Airlines to register me for online check in. Missed check in (Pattaya road construction, slow taxi driver, long check in queue). Travel insurance is only good for medical reason so now I get to purchase a new round trip and throw away the return leg. 
Two different airlines. AA and Qatar.

My niece used to work at AA (and STILL flies for free). Hoping to get advice from her but she’s in Rome vacationing and not getting my messages yet.

She did say if you don’t buy from the airline not to expect much. 
I thought the taxi would only take an hour and leaving Pattaya 4 hours early would be no problem with three hours early.

Not fun indeed. Hopefully there won't be a next time but if it would happen again I would do this:

If the check in deadline approaches, buy an AA ticket, check in online & charge back your BudgetAir ticket.

sorry to hear about your troubles. I know somebody who had similar case many years ago. Few years ago on one of our forums reported that he was stuck in traffic owing to car accident on the highway and barely managed to catch his flight even if left with ample time .

It's why I'd not entertain other option than spending at least last night before departure in  Bangkok. Less nerve wrecking

6 hours ago, t0oL1 said:

if you don’t buy from the airline not to expect much. 

Unfortunately for you, your niece is 100% correct.  Third-part ticket brokers can offer very good deals but I try to buy only direct from the airline for just that reason. 

Of course, post-Covid, I know that there are a million stories about people failing to get refunds from the airlines.

Here's hoping the situation works out for you. 

Had to message a friend in USA with credit card and passport numbers. She could buy a one way ticket for Friday morning for $966 includes insurance. I was guessing $8000…