Hi @WTagreen!
I think what could help here would be something like the webhook module in Integromat. Webhooks essentially subscribe you to an event (in this case, any updates and new rows created in your Google Sheet).
Once an event takes place, your webhook can then trigger another action (in this case, a new item to be created on your monday.com board or updating an existing item).
Could something like this help?
I see that Zapier also has their own webhook app, so perhaps you can utilize the Zapier one instead.