I'm trying to upload a WebGL game made in Unity and can't compress the data file enough to upload.

I have deleted unneeded files and limited the size on my textures, but don't know what else to try.

This the message I keep getting:

There was a problem loading your project:

Zip contains file that is too large (WebGL_Build2/Build/WebGL_Build2.data.unityweb)

Please try deleting the ZIP file and uploading another one.

Desperately need to get this uploaded for my uni course work and would appreciate any advice!

Thanks

Try using Butler. I can't help you with it, but among other things it gives you a higher upload limit outright.