Give him time, don't expect quick magic. Good training is never quick, in my experience at least. I had a similar story with my horse. I bought him on his 5th birthday, and he had last been handled on his first birthday when he was sent to his previous owner's and in between he sat in a pasture.
I used a trainer as a mentor, but participated in much of the training as the body. Trainer's brain, my body. We spent three months on ground work... THREE MONTHS before someone got on him. I was very upset that it took so long, but when I got on him for the first time, I was sitting on a horse that was 'broke'. He tensed up when I first got on, and was pretty nervous, but I already had turns, brakes, backing, and go.
While training can take a long long time, I think spending more time on the beginning stuff can really help a horse in the long run.
A horse with constant handling that trusts people may be able to do all of that within a month and a half. Our horses didn't have that start. If I were you I would find a trainer willing to start over from the ground, and do it slow and easy. A month and a half is far to short for a horse that came from the background both of ours did.
"Putting pads on a gaited horse is like putting a mask on a beautiful woman."