I guess you have not read the other chats. You can get 45mm blades at Harbor Freight for $1.49 for a pack of two.
They are called carpet cutter blades but they work in most cutters.
Right now so many quilters have found them they are on back order but in a few weeks they will be back.
Just look up Harbor Freight on the computer and then look up strore locater.
If there are non close to you, they can be ordered on line.
If you have a store close call to make sure they have them in stock first.
Good luck.