I haven't been in your exact shoes so forgive me if this sounds judgmental. I have worked remote for several years and if there's one thing I can say, it's that I don't think your job is your problem. The problem is that you don't feel challenged, and you're expecting your work to fulfill that for you.

Find a way to fulfill that on your own. Start a blog, side project, or a hobby. I have all 3 going, plus more. Work is where I get work done and support my family. LIFE is where I get fulfillment ;-)