HerRoom Response: According Marie Jo's European sizing you actually went down two sizes. You should have bought a G cup, however Marie Jo does not offer G cups so this isn't the right brand for you.
You may not know this, but many manufacturers call your cup size by other letters. For instance, some manufacturers refer to a DD as an E cup, a DDD as an F cup and so on. If you need help deciphering what your cup size is, please see our size conversion chart, which lists each brand's cup sizing guidelines: