Item Glitch

I was just on a MC server in creative plots so I saw a random plot and I started braking stuff.
But Like always it would say "you can't build here" and then would just put the block I broke back. But I kept doing it and then it stop. So I freaked out and TRIED to get a Grass Block but when I tried to it wouldn't give me 1,ONLY if I hold and drag the item I wanted,But it got worse I can not drag the item and put it back in the invintory. And now I HAVE to have lava near by to get rid of the item in my hand. (p.s the gold ore saying yellow wool is not part of it ;p)