Hi,
I'm new too so please wait for advice from more seasoned people, but I think you just gave a very strong case for grad school.
You had eh grades because you were missing a direction, which you found, which can be supported by the field work and online classes. You have a professional project/passion and you actually have evidence for your narrative.
When you apply, it's okay to explain where you're coming from but I would avoid dwelling too much on your anxiety and insecurities -- nothing wrong with that, but your SOP should be more about how you're striving to be where you want to be and how you're doing it. On a separate note thanks for sharing, late teens/early twenties can be dark.