You may not be able to continue reading a English newspaper not only because of lack of vocabulary but also because of lack of knowledge about the incidents. Actually many people advised me to read a English newspaper; however, I did never succeed in continuing because it was very difficult to imagine the meaning of unknown words when I did not know about the news at all. I became at a loss only because of one unfamiliar word easily. If I use dictionary, the situation will be worse. I have never had patience to take out a dictionary in a crowded train and look up all the unknown words. Frankly speaking if you have knowledge, lack of vocabulary will be compensated by your imagination. Consequently, you'd better do a little preparation in order to make your imagination work at its best.
You may think that you have to read English magazines or newspapers to collect information. Don't worry!! I am not suggesting that all you need is patience. Please remember that you have learned a lot in your native language since you were a child. You can use your native language to collect information. Watching Japanese news on TV while having breakfast, reading a Japanese newspaper on the commuter train or browsing through a Japanese news magazine will help you a lot to get knowledge. You also can use English news magazines which are translated into Japanese and published regularly. This is so much easier for you than continuing the painstaking work of reading English newspapers or magazines.
After getting basic understanding of the news or the articles of Japanese newspapers or magazines, it is time for you to sit and struggle with English. I strongly suggest that you use TV programs with English captions as a text. If you watch TV, through receiving information from several media, you can practice using all your abilities to understand what is being said. Here again, the key is imagination. TV pictures stimulate imagination and help you to understand the content of the program. And captions help you to find exact words for what you imagine and understand through pictures and what the announcer says. It is advisable to record the English news if you are in Japan, because English news with captions is very scarce in Japan.
At first please try to catch as much as possible without reading the captions. If you follow the captions from the start, you can not listen to what the announcer is saying nor watch the pictures at all. They give you so much more information than what your eyes can catch through reading. After that, watch the news again and check what you missed the first time using the captions. This is the moment that your imagination becomes a real word. If you do not know a key word, look it up in a dictionary. This helps you a lot to gain new vocabulary. Besides that, you find it easier to remember words which you learned this way. You may even find easier to read English newspapers after this practice. The same key words usually appear in newspapers and if you keep doing this practice for some time, you will find that unfortunately almost the same kind of incidents happen repeatedly in this world. This means that next time when you come across the same kind of news, you do not have to look into a dictionary.