I do recommend trying from a different connection. Any download can only be as fast and reliable as the slowest link in the chain, which is usually the downloader's ISP connection.
We use Amazon S3 to store and serve downloads on a long-term basis, which is about as high-performance and robust a download service as one can get. After you upload a file, or after the first download of a remotely-hosted file stored on your server, within 15 minutes we have a copy of that file synced up to our S3 provisions, from where all subsequent downloads of that file would be served.
Many consumer-grade ISP connections advertised as "high speed" only provide their maximum rated speed under ideal conditions and/or for brief bursts at the very start of any download connection. This initial-burst speed is suitable to accelerate routine Web browsing, as most Web pages and the images and other content embedded in them are generally rather small files, but larger files would only see that max speed as the download begins, which quickly gets throttled down to a much slower speed as the download size exceeds anything that would normally be viewed as a Web page.