how do i fix this?

Yes, that's right. I remember when I used to read novels; when the author went on too long without any dialouges I found myself drifting away and getting 'really' bored.

Plus, a chapter without dialouges and another loaded with dialouges and on and on........not very effective, no.
I think you'd have to write it again.

Hope it helps.

LEENA

Unfortunately your first hundred pages are very important in convincing a reader that your book is worth reading.

I appreciate right now that revision sounds like a lot of work to you, but you can't expect hundreds of thousands of readers to wade through 100 dull pages before you show the story-telling craft you've learned.

If you want readers, you have to cater to readers.

...
well it depends on the kinda audience you're aiming at. but there is a huge majority of readers who basically only read dialogues and skip the rest of the text...so you might loose their interest if your first books first 100+ pages contain no dialogues. (sometimes i also fall in this category)

you said that your story is a murder+politics based... your main audience seems to be young adults and teenagers_ who are VERY concience about dialogues.
so... it's up to you...

I agree...it is up to you. However, to keep the momentum of the story going, the entire thing needs to be written in the same format. Meaning: if you have the first hundred pages written as narrative/dialogue/narrative, you need to have the whole thing like that. You can't just all of a sudden change the format of the 2nd hundred pages to have sporatic dialogue. Otherwise you're going to confuse your readers. And that's not a good thing to do.