Media storage

We have purchased a collaboration license for our textbook and are having a serious media upload issue. I have reached out by email to Pressbooks twice and had no response. We have 11 JPG images (<2MB each) uploaded into our media library and are prohibited from uploading anymore. The error we are getting says that we have used 1100 MB of storage, which is beyond our 1GB cap. We are using H5P plug-ins to add interactive elements to our book, but cannot see the file size of those.

Can someone help me? We would like to purchase more media file storage or have someone help troubleshoot this. We are making a free textbook for Anatomy and Physiology college courses, and have amazing illustrations we would love to share with students around the world. We just cannot fix this issue, which is preventing us from finishing our book.