I also feel a trainer is needed, you would be amazed at what a few 35.00 lessons can teach you and your horse... training doesn't have to be expensive.
I also agree with going back to ground work and lots and lots of desensitization. If you have a roundpen I would go back there until you can get blankets, ropes, leads, yellow slickers, etc all around him, over him, under him while he walks, jogs, lopes at your request. The time it takes is necessary and as others said, builds trust. Put him back in a snaffle if he is in anything else and bit him up, teaching him to give and carry himself in all gaits calmly.
I wouldn't get back on him again until you get the above mastered. Horses can be very dangerous, and a scared horse is the most dangerous - they aren't trying to be mean, they are trying to get AWAY and will do whatever necessary to do so. Desensitization will help him control his fear and help you stay safe.
There is no passion to be found playing small - in settling for a life that is less than the one you are capable of living. - Nelson Mandela