Older bikes have what is known as a quill stem. The stem telescopes inside the fork steerer tube and is held in place with a wedge. The long bolt you removed threads into the wedge. When the bolt is tightened the wedge is pulled up.
What you should have done is loosened the bolt, aligned the bars and re-tightened the bolt. With the bolt removed the wedge is not longer attached to the stem. It's either dropped down lower in the head tube or is stuck where it was. You should be able to get the wedge out. Out the stem and look in the head tube with a flashlight. It may simply drop out if you turn the bike upside down, or you can tap it loose with a hammer and long screwdriver or the bolt itself.
When you get it out, reassemble the stem out of the bike. You want to clean and lightly grease the bolt, stem and wedge to prevent things corroding in place in future. With the bolt loose, reinstall the stem into the bike, adjust stem position and tighten the bolt.
The bend in the bolt might not be an issue. I'd be more worried about the state of the threads and the ability to tighten the bolt up hard enough to lock the stem in place.
There are lots of YouTube videos on all aspects of bike mechanics. Here a good one on quill stems from Park Tool.