The puppy

The puppy suddenly started flipping out when my mom isn't home at night a couple weeks before the old dog died.  She used to sleep in the room with him and it helped somehow.  But now I have done everything I know and he is still barking.  He slept for a while but if I take a deep breath he wakes up.  I even gave him a little sedative.  I think he's getting a little more.  He is so wound up that he's never going to shut up and I need to get downstairs to get water so I can take my pills (way late because of him) and I can't take the barking anymore.  I have in the course of a month tried everything.  Leaving him alon in his crate feels mean but it does not good from me to be laying there while he barks at me.