The best thing you can do to improve your reading is read more. I know this sounds simple and unhelpful, but if you just stay the course at keep at it you will get better. Try reading translations of books you have read in your own language, or the book of a move you like. To be honest, kids books can make for pretty good reading sometimes. I like them for improving my reading in my languages.

If you stop reading something because it's too hard, then choose something easier. Read something appropriate to your level. You may want to read original material, novels, internet sites which suit your interests, but you may not yet have the level to do this. There is "graded" material out there for adults so that you can read material suitable for adults at a level which is right for you. Coursebooks are the perfect example of sources of graded material but it can be limited in terms of interest. Don't try to understand every new word or check every word in the dictionary. This will slow you down too much and demotivate you. Read for the general meaning and just notice words or structures which you have previously studied.