I'm a native speaker, and quite often I find it difficult to skim or scan an article and still understand the meaning. I'm one of those people that needs to read the whole piece in order to comprehend it. The one advantage is, after many years of having to read the entire piece, my speed has increased. The only advice I can offer is to continue to read everything you can, and if it means reading word-for-word (instead of scanning), then do so. The more you practice, the faster you will get.