What should I do after being denied entry to Thailand on an ED visa, and what are my options for re-entry?

Hello all. Reporting in yet another denied entry at Suvarnabhumi on ED visa (1st). My visa history to get some perspective on the current situation. I have 6 VOA's dating back to the first in early 2016 and 5 TV's 3 of which are back to back. This latest visa i applied for in LA my hometown.

Flew into Suvarnabhumi on March 3 (left BKK to visit family on Feb 2, 2019). I cue up in normal immi line and handed all docs to female IO. She paws through my passport and calls for another IO and im taken off to the side. I meet another IO and she starts to look frustrated as she looks at my passport. She says 'you stay too many times'. She looks at the docs for my ED visa and puts them aside. She then goes silent. I ask her if I have all the correct documents and she sends mo over to sit on some chairs located next to the office. Im sitting there for quite sometime and start messaging my thai gf letting her know of the situation. The IO is ignoring any of my questions so i hand her my phone with my gf on the other end. They talk for quite some time the IO hands back my phone and my gf is crying.

Another IO comes by picks up me papers/pp and starts guiding to some back room of the airport where there are four dudes doing paperwork. After sitting there a lady comes in and calls my name. She works for the airline i flew in on. She hands me a piece of paper and says 'sign it'. I ask her what i am signing. She doesnt say anything. After i looking over it for sometime i gather it says i dont have 20000 baht. I refuse to sign as no one even asked me to see cash. At this point I start to get upset. From there Im taken to a detention facility. No one is informing me of the situation. After sitting in the detention facilty for 30 min i figured they are just gonna leave me here. I ask the officer over and ask them what i need to do to get out. They say buy a plane ticket. I do just that and show them the proof. They keep me detained until my flight and then im ushered to the back of the plane by the officer and FA, what a terrible experience...

So here i am back in the states. My passport was stamped with a denied entry. I hope some of you can offer some suggestions and answer a few q's I have?

What are my options for re-entering? I see alot of suggestions stating doing a land border crossing. This makes sense as it prevents a flight back if denied again.

I still want to use my ED visa as I actually want to learn the language. No marks were made to the visa so im assuming its still valid. Am i wrong here?

I will be prepared with all docs and 3 proofs.

Apologies for the long post. Any advice would be greatly appreciated.