Hey, don't be discouraged! When I got my first 2 horses, the one that was absued and spooky as all get out became my project. I went into it expecting troubles, whcich I did run into frequently. But I tell you, one thing will help you more than anything else-
Join Up. Or free lunging. Or whatever you want to call it. Here's a good start:
1) Take him into a roundpen ( trust me it's so much better. When I first started I had to run around the whole darn arena to keep him going), and work him. Work him work him work him. Keep him trotting, and if he canters, that's ok, because right now, controll is not the issue. Let him run. Let him run till he gets tired and only wants to trot. And then keep making him trot. Work him until he dosn't want to work anymmore. Watch his inside here almost caonstaly, eventually, that ear will almost always be on you- which means he's paying attention to you.
2)But that's not enough, Keep him going. It's ok if he sweats, the whole point is to make him go go go until he dosn't want to "go away" from you anymore. He When he starts relaxing his head and his ear is always on you, stop chasing him, and watch him. He should stop and face you, maybe even walk up to you, although he is more likely to do this if you turn your back to him. But before you attempt to ask him to follow you, come up to him qand rub his forhead, and then walk away and see if he follows you.
Montey Roberts and a couple others whom I greatly respect say this should always be the end result. I dissagree. My horse never lowered his head and licked in chewed. It just wasn't in him. But eventually, if I put my hand under his chin and drew his head forward and THEN walked away, THEN and only then, would he follow. But the one thing you look for is the turning to face you. That means he respects you some, if not completely.
3) Now, if he does no follow you, or backs away- or lunges at you- when you approach him, then send him off again. And start the process all over again. Make him go go go. Let him know YOU are alpha. This is nothing new t them. This is herd hierarchy. The lead mare does it to insolent yearlings. All horses understand it (There's always an exception or too though). This is not cruel and unusual. Sometimes it take a horse a couple of sessions. That's ok. But keep doing this until you get the desiered result or you can no longer chase him because your too tired ( that's how liong it took with my horse).
Now, this may take a couple days, maybe even a week- Duke was terrified of humans and loathed them with his very existance. It took him a long time to accept me as alpha- AND trust and respect me, which is your true goal.
You can IM me or email me anytime if you have any questions. firstname.lastname@example.org