Good for you for realizing that the horse bonding process is slow and most of us, even those with experience have our growing pains. In my years of experience and observation it seems to take an average of about 3years to really get that bond going, and everything you do during your horses lifetime will make it's mark on that bond, either positive or negative.
Now, looking at your pics, I agree with the stirrup comment, but I also want to make a comment about the bit. It may just be the pic, but it looks like a leverage bit, and IMO those are for experienced hands and an advanced horse. Especially with a bolter, you want a lot of lateral (side to side) control. It is hard to get that with a long shanked bit because it is not a direct line to the horse's mouth......the shank gets in the way and confuses the signal. It may not seem to make sense to you at first, but go back to a basic snaffle, and work work work on lateral control in an enclosed enviornment.
Work first on flexion, then disengaging the hindquarters, then you can start practicing the one rein stop mentioned earlier. Practice it at a walk, then trot, then canter until you can do it in your sleep.
When a horse bolts, you really need to catch them during those first couple of strides that are out of control, otherwise, once they really get going, you will need some space to start circling them down, and you may not always have that. In other words, the horse goes to take off, and you get that head around immediately, disengage the hindquarters, and then decide what you need to do from there. Disengaging the hindquarters shuts them down long enough usually for you to evaluate the situation.
If you feel you are in immediate danger, get off. If you horse was just testing you, put him back to work. Working with a bolter takes some nerve, but most will knock it off when they realize they aren't getting anywhere. As others said also, working with a -good- trainer will also help. Hint: a good trainer will not suggest you put stronger and stronger bits in his mouth.....should be the opposite....going back to basics as I mentioned above. Best of luck to you, and be careful