Wrought Iron gate dragging

Pull the top of the fence post back

This

Clever.

In the summer drought, many posts with pressure on them will lean, simply due to the ground pulling away from the concrete.

2 best solutions are to either buy an adjustable gate wheel, or add more concrete to the footing of the gate support post.

With the post leaning, you need to address the post. Is the post not tied in with a fence?

I recently welded a metal fence around a family member's pool. I had a double gate and once I got it all set and welded on, one of the gates had a bit of a sag in it. I ended up cutting a quarter of an inch of the top rail out and cinched the metal together and welded it back up and it was perfect.

This would only be a patch fix for you because that post will continue to lean more and more. The best option is to add another post a few feet away and add a gusset post from the bottom of the new post, to the top of the leaning post.

An alternative to the wheel idea is to add a support for when the gate is at rest. The post likely won't lean while the gate is between swings. It's the sustained weight at rest that moves it over time. So if you can support the end of the gate while its at rest, it shouldn't move on you unless the post is not properly fastened in the ground.

Alternate that worked for me, I drove a steel rod into the ground with an eye bolt on it. Then drilled a hole through the post and pushed another eye bolt in. Connected the two ends with threaded rods and a turn buckle. Occasionally adjust the turnbuckle but it has been solid.