Nice attempt man, Though here is something for you to chew on when you think about another seemless texture..
The image that you created has to many large comsetic marks for it to look good as a sseemless texture..sure it'll look good on one segment but place that one 5 segments one a wall...notice how always see that blem?
Try this...
Open <insert image editor name>
Go to create new. create a new ducument that is H512x W1536.
Now create a seemless texture...once you have made the image the way you want it..select the maqruee tool...select an area that is 512x512 then copy that selection... then go to file>create new and select ok. it will opne a new window that 512x512.. now paiste the image in to the new window. now save this new 512x512 and name it something like "one" and then go back to the original image 512x5136 and select the next area with the marquee tool (remember 512x512 areas) and repeat the process...
when you are finished you should have 3 512x512 images tthat will tile together...(notice 512*3=1536)
Cheers!
RF