First & foremost OP, keep your safety in mind. I'd advise you work with a good trainer with him for now, so they can evaluate what's going on & show you what to do.
This horse may be purely telling you where to get off, or he may be in pain, which is why he's so reactive. So I'd also want to rule out/treat physical probs before treating it as a training exercise.
I'm more in line with Redbear's first couple of sentences. That is, I find it very effective to use 'clicker training' principles to turn screaming Mimis into well mannered, willing ***** cats
, I find 'approach & retreat' a very effective 'tool' at desensitising horses to stuff without confrontation too. However, if you're not practiced with this sort of approach, again, I'd find an instructor to teach you first, because this is not the sort of horse to experiment on & inadvertently reinforce the Wrong behaviour. It sounds like this horse also needs a firm approach, but considering your safety, I don't think trying to force him into stuff, especially loose, is a good idea.