Since you spilled so much, I wiping off excess or rising off excess sauce and food particles. Then using a mix of dawn dishwashing liquid (or equivalent) as a degreaser, dye free liquid laundry detergent (or powder mixed into a runny paste), and oxiclean (or other powdered oxygen based bleach) and liberally applying it to all stained areas. Let it sit over night as a pretreater, and then soak it in warm water for a few hours. If you can't keep your hand in it for more than 10s, it's too hot. Repeat. If you prefer not to soak, cover with a damp towel and keep that towel damp.

See if you can get your hands on one of the following brushes... they are softer than a traditional tooth brush, and are great for cleaning fabrics

Natural bristle laundry brush https://www.amazon.com/dp/B0B3MJ44KZ

Soft bristle plastic tooth brush https://www.amazon.com/dp/B085CJHSHJ

The following is good to have, but may not help you in this specific situation.

Enzyme based cleaner https://www.amazon.com/dp/B083WN1GW/

Links to Amazon are examples of products, purchase elsewhere or choose similar products at your discretion.