Sounds similar to my girlfriend. She gets overwhelmed with how much she has to do that she freezes, then has a panic attack because nothing is getting accomplished. I help by picking whatever seems most pressing and telling her to focus on that and nothing else. When it's done we pick another thing.

I'm sure this isn't groundbreaking advice (or even good advice, "just do the thing" yeah no shit), but if you struggle with getting started it might be worth to ask someone to handle organizing the tasks for you.