Not to worry! You can use a 3D printing service such as 3DHubs or MakeXYZ to have a local 3D printer operator 3D print and ship you parts to you. This is a great way to get your parts 3D printed by local makers. You could also try checking out your local Library or search for a Maker Space.
You might also consider modifying a project case or box of similar dimensions for this project.
There are three pieces to print: the main case, the lid, and the divider (print two of these). Files are below. The lid and dividers are flat and don't need supports and require minimal cleanup. The body needs full supports (from everywhere rather than just from the build plate) and will take a fair bit of careful cleanup to remove them.
When slicing, orient the body so that it opens up, and the lid with the rounded edges up. The divider should already be oriented flat.
If you have heat seatable M3 inserts they can be placed in the four bolt-holes in the top corners of the base.