your in for a long journey, there are no magic or quick fixes - stay way from meds of any kind. Try crate training. start with small increments of time, make the crate a fun and safe place (i.e., start with 10 minutes at a time with a snack - i use kongs that have been filled and frozen with peanut butter. Then move to 20, then 30, then 40, then an hour, then two. always make the crate a safe fun place, not a punishment place. try having your pup sleep in there at night. my two new pups are almost a year old and they still sleep in the crate.
It takes time and lots and lots of patience. good luck!