any help would be appreciated!

car is a 99 civic si
i was driving 10-15 mph and all of the sudden check engine light comes on instantly the car shuts off. i push the car back to my friends house and start looking for the problem i figured out that the fi em and back up fuse blew in the engine bay to i replaced them to find out when i turn the key in the acc position the fi em fuse blows.

i checked various things and figured out when i disconnect the main relay the fuse will NOT pop but as soon as i connect the main relay the fuse blows. i tried a new main relay but the problem is still there. so i went ahead and took off the engine harness to inspect it and it is alright. checked all the grounds ect.

what i figured out is when i disconnect the main relay it will not blow the fuse, if someone can help me with this i would appreciate it!
also i did not have a check engine light on and now it is a solid cell and i can not check what the code is since the cel is solid