Ewww, all of these are just green horse issues and unfortunately he is a little old to be having so many of them. It seems what your really frustrated about is his whole getting it one minute and then not another. You may be communicating perfectly but he is just trying to evade because submitting to a rider is new to him. The reason he is getting it for a minute is your are blocking his evasion, but that doesn't mean he isn't still trying to think of another way to get out of it. I felt frustrated in the same way when I broke my mare because I had her since birth. I was hoping that she would advance really quickly because I had done so much groundwork and schooling, but she still acted like a three year old. I gave up on ring work all together for a while and just took her on the trail so she could get over her spooking, mud, peacock, baseball game, barking dog issues. It really helped, but it wasn't my choice of things to be doing, I had pictured us laying down flawless AA Hunter rounds by 5. Now she is an extremely trained horse, suitable for small children, but she's 10, and she still can't do a flawless AA round, but I love her more than any other horse. It was a labor of love, and I haven't really wanted to go through it again, but probably would if presented with another one I loved like her. Your going to have to either be patient, even if your not understanding, and time on his back is what he needs right now, even if it's unstructured. Maybe go out on him and don't ask anything of him, other than he's not go right back to his stall, but let him stand if he wants to stand, walk, explore, he might forget himself and that your on him, and drop the act or get curious about his surroundings. Pretty soon he might think it's not so bad because even though you insist on riding him, he kinda gets to choose the activities. That's just a recommendation, not neccesarily a solution, a trainer would probably be important at this point if you decide to keep him. And if you decide he's not fun for you and your scared, than finding him a good home is best for both of you. We had a WB once that hated his owner, just because of personality, but loved me, because of personality. Drove her crazy when he would spook at a tree a hundred times with her and then I would get on and it was fine. He was just smart, knew how to push her buttons, I thought he was funny, so it didn't get to me the same way. Personality can make a difference and horses are supposed to be fun.
Troubled TB ~"A thorn by any other name will prick just as deep." @-'--,---