Is it nessasary to have a root canal done before a crown build up with pins?

I have had 3 other crowns and never had this many problems.  This 4th crown
is a bear and I have numbing from above the crowned tooth along my cheek bone
down to my upper lip.  Is it possible the dentist inserted the posts to deep
cutting off nerves and feeling to my lip?

After a month I finally got my new crown that was metal inside installed with
out novicane.  After only a few hours my head felt like it would explode.
Everything hurt, anything hot, cold, even just breathing caused pain.  I went
back to the dentist the next morning to have it cut off.  Every muscle on the
right side of my head felt like it was flexed or kept tense for the 26 hours
I had this crown in.

I have a temporary crown in again, but my lip is still numb and tender to the
touch.  The temp. crowned tooth contantly has the feeling like when you touch
a metal filling with a fork or something metal.  A metalic taste and the
strange feeling that this metal to metal filling feeling gives.

Do I need to go to another dentist?
PLEASE HELP!!!
Thank you,
Kim (aka SSB)