Help with Schema

Schema is all messed up on one of my websites and I need some help.

The rich snippets for every page of my site besides the products have star ratings. Only products should have star ratings. Also, all my products say that they are free in the snippets. Which I can't change.

The website is built with WordPress and the Divi Theme. I can add schema in an integration area inside the Divi Theme however that code gets stuck in the header of every single page on the site.

Also, I have Yoast SEO and WooCommerce active on the website. These plugins inject their own schema. I don't know how to not have them do that.

I am trying to test out implementing schema through the Google Tag Manager. So far I haven't seen it fix my rich snippets and people online say that it's not a good idea.

Ultimately, my question is how can I get the schema I want per page on the website?

You could hack at the templates in WordPress, that would take a while though. Schema can work through GTM, there's a case study on FAQs being marked up. It did cost someone a lot of traffic however. Schema is a way for google to take your content.

Schema tag is very helpful for the ranking on the Google, Because it shows the star rating from the customer.