Reading should be fun, so make sure the texts you choose are not too too difficult for you. If the book or article you are reading is a chore, then find something easier.
Find an author you like and read all their books. By doing this you will get used to the style of a particular author and the typical vocabulary and grammar they use. As you read more of his/her books you will find it easier and easier.
If you have a local library find out if they stock English books or if they have bilingual editions of English classics. Or ask them to stock English translations of books you are already familiar with.
Try reading things more than once. Read something and then read it again a few weeks/months later. You should find your understanding has improved.