The Bunnings Workshop community can help with your home improvement projects.
Hi @Co0ki3,
Please post photos from further back so we can see the whole thing, likely the line will need to have it's own support posts.
Cheers
Hi @Co0ki3,
Welcome to the Bunnings Workshop community, it is fantastic to have you with us.
As @AlanM52 mentioned, some photos from further back would certainly help, but you can see that the fence rails were originally screwed at an angle into the post that is attached to the brick wall.

There is evidence of the same situation on each rail, but there is no visible screw like the one above.
Without seeing the whole picture just yet, it seems like the simplest solution would be to reattach the fence rail to that post, then simply tap the palings back into the rail.
You can refix the rail to the post using galvanised screws and galvanised angle brackets.
If the fence rail is only part of the problem and the lean is much more severe, then we will have to see the bigger picture to propose methods of reinforcing the fence.
I'll wait to see what you think and assist further if required.
Jacob
Workshop is a friendly place to learn, get ideas and find inspiration for your home improvement projects
We would love to help with your project.
Join the Bunnings Workshop community today to ask questions and get advice.