u/Headshot_Harambe

This is an old stain (I think curry) on a cotton Shirt that I really like.
I'm not sure how I got this stain but since I usually only wear it for wedding functions, my best guess would be curry stain (Turmeric, coconut, chilli, pepper and other spices combo)
The stain is over 6 months old.
The shirt was probably ironed once after that.
I tried baking soda + Lemon + detergent + Hydrogen peroxide combo but the stain did not even fade. What are my solutions?