You've invested a lot of time and effort into your story so far, I know because I have gone through it and I am currently going through the process again right now.
There are literally tons and tons of children's book illustrators at your disposal thanks to the internet. That said, the process of sifting through and finding children's book illustrators can be an arduous task.
If you are going through the traditional publishing route and trying to find an agent to publish your kids book, then they will also help you find illustrators that will be a good fit for your story. If this is the case, focus on finding your agent or publisher.
If you are planning on publishing your book yourself via Amazon and other sites then you have a little more work to do here. There are quite a few places to find illustrators on the web these days and here are a couple:
Dragons Love Tacos is the latest children's book he illustrated. I am huge fan of Dan's art and definitely encourage you to check out his work!
If you aren't having any success, just do a Google Search and look for illustrator websites and find some art that stands out to you and matches your vision and contact them.
I hope this article helps you find the illustrator for your children's book and the journey is as painless as possible
If all else fails, you can always reach out to me if you like my style and we can discuss the possibility of working together.