Max quota reached problem on multisite main site


I am a little frustrated, I had put so much effort configuring pro sites, but it has given me so many problems, the latest one, I cant upload new themes to my multisite as network admin, it says I have reached the max quota allowed, on the main site!! so I changed the main site from unmanaged to a plan with 20gb upload limit, and I still get the error, so I uninstalled the pro sites plugin, but I still have the same problem, I can't upload new themes, even with the plugin uninstalled, I did not have this problem before, I would appreciate if you could point me in the right direction. please.