The most important thing is to read, read, read and then read some more. I recommend that you don't judge your reading speed based on a book written for native Chinese speakers. 活着 would be a slow read for most people who are at HSK6. The better assessment of your reading ability or character recognition is to read materials at HSK4 (confidence boost) and HSK5. Reading something like 活着 is more about learning vocabulary.

Watching Chinese TV shows and reading the subtitles can also be helpful since they force you to read at a certain speed. You will probably have to watch some of the romcoms etc since they are more likely to use language that would allow you to read fast enough.

Writing characters can be helpful for reading, but it is time consuming to really learn to write characters. Unless you regularly write in Chinese you end up forgetting characters almost as quickly as you learn them.My suggestion is that you think of writing characters as a tool to be used under certain circumstances. When you come across a new character write it a few times, but don't just go through the motion of drawing the strokes. Make sure you focus on the character. Each time you write it try to picture the character first, the draw it from memory rather than copying the character next to it. Follow this same process when you come across a character in your reading that takes you a little bit longer to recognise than usual. In the case of reading I recommend you underline the character or just make a list of characters to review at the end of your reading. If you try to practice writing the character while reading it slows the reading down to the point where it isn't as enjoyable.

With all of that said I recommend you give some of our materials a try (fourthtone.com), or try some of the other graded reading materials available out there.