How can I make the texture look more seamless?

[akashi1]

It looks very blotchy. Like I don't want it to show a repeating pattern.

[Svetlozar Draganov]

You may try to mix it up with other textures, this will certainly help to break down the repeating pattern.
Another option is to prepare of find another a larger texture where the pattern is less repetitive.

The following Photoshop technique is very useful to build seamless textures:
https://medialoot.com/blog/how-to-ma...otoshop-redux/