I had a similar problem when I was collecting guns,early Winchester and Colts.
It was completely out of control. I did the same as a lot of you, just about all my free time was spent on the computer looking for guns, and going to gun shows everywhere. Almost all day long I was preoccupied with them.
It turned a fun hobby into a complete obsession. The satisfaction was in the looking, locating and buying. As soon as I got it home, cleaned it and put it away, the search was on again...
Fortunately the knife thing has not gotten as bad. I feel for anyone that has gotten themselves into a financial hardship because of their addiction.
Sounds like you are working hard to fix the problem.
Good luck, its very hard thing to do