it's hard to creating an original artwork

I totally agree, but maybe not for same reason as you? I myself wrote a short post just yesterday asking if it's not so that art keeps repeating itself. I noticed that some things I have created has already been created by other people. Sometimes I'm first with the upload other times I find my thing have a strange resemblance to other works.

Look here at my upload of "Insides" (which was first): [link]

Similar perception, however I had no intention at all of even reproducing the ideas of what this artist made: [link]

An beautiful painting made by mariamism: [link]

Something I made quickly in bed on my phone long that artist made an upload , but I had not seen the image at all. You see the common shapes of grapes, snake like shape and even the peacock feathers eye is in same position! Similar usage of colors too I can't explain it.
[link]