My understanding is that e=mc2 is for objects not in motion.
The full formula for all objects is said to be :
e2=(mc2)2 + (pc)2
Where p is the momentum of the object in question and c is still the speed of light like in the mc2 part.
A great visual of the concept using a right angled triangle can be found at the following link:
https://www.britannica.com/video/185388/equation-theory-energy-relativity-mc
Neat idea, but i do not believe this works.
First of all, i do not believe in the theory of relativity.
Second, i believe that matter is slowed down light. (kinda sorta)
Third, there is a consciousness component to it all (double slit experiment)