I am playing survival. At first I could break blocks and do all sorts of things but now I can't. First of all I am not playing in adventure mode or anything. I believe it is a glitch of some sort. This problem initiated when minecraft crashed. Please HELP!
Create a new world and see if that fixes it, if not simply "force update" Minecraft by going to options on the launcher. This will install a clean copy of Minecraft. You may also want to check that your controlls are all in order.
This happened to me and my controls were all weird (like space to hit). This also happened after a crash.