I have massive amounts of organic traffic, but I am struggling to monetize my app and website.
Re-visit your marketing strategy. Which is to say - re-visit your business model (which should very directly point you in the direction of your highest probability marketing strategy).
And (get ready to not like me for saying this...) stop focusing on those numbers. The number of visitors per month and the number of downloads are only relevant as they directly relate to conversions and sales.
And those things are only relevant as they directly relate to bottom line revenue and margins.
It's easy to get caught up in "vanity numbers"... those numbers that "feel good" and provide you with a sense of validation. But until and unless they translate into bottom line income for the business they are just numbers that make you feel good (versus wisely chosen key metrics that indicate the health and viability of your business).
If this was helpful to you please let me know how else I can be of assistance.