How to get rid of that seam in the middle? When I create a seam it still does it, and when I just unwrap it, it also does it. This is just a painted texture and its only my second one so that’s why it doesn’t look great btw.
Unless it’s a tiled texture it won’t matter where the seams are. Your best bet is to use the clone tool in texture paint mode to match it up. Or actually paint it by sampling colours. If you still see the seam while painting try increasing the bleed slightly until it starts to blend. Just don’t go too far with this value if you have the uvs packed closely together.
Aside from that you could use procedural textures that won’t require uvs. But that’s another discussion, best left to someone with experience in that area. 
The same process I mentioned in your thread about the cube.
maybe overscale the uv’s in that direction!