Hey, welcome to DA. Seeing as you're new, I thought I'd give you the lowdown on what happens on here...
BASICALLY, you upload original artwork, stuff you created, I'm afraid you're not allowed to post existing work from other artists... So thats why you're getting so much flack from people about the skull image. It is a wonderful image! But the pieces you post on here have to be your own... I'd advise you take them down before people get angry and such...