A crate is like a den to a dog- it is NOT doggy jail or prison. And it will save your relationship with your dog.

Also a puppy can only 'hold it' for about 2 hours longer than his age in months - i.e a 3 month old puppy can only hold it 5 hours.

A gate on the kitchen won't work because the area is too large. Dogs don't want to get their feet in the stuff or lay in it - so a crate (using a divider if necessary) and having it just big enough to lay, stand & sit in is the easiest. It is 'their' space - where they are safe, etc... Cowboy goes in on his own to sleep when he is really tired. Do not use bedding a towel etc in it for now... that would absorb any accident and he can still stay dry.

After being crated - take him out immediately for now - he'll learn quickly.

Also, take his water and food away about 2 hours before your bedtime - and give him a quick walk before you head to bed. When you come in, crate him immediately.