hello again

I still facing problems in my simulation  >:( >:(

my problem is with the very small value of the mass and charge of the proton
charge= 1.602*1e-19
mass =1.673*1e-27

that when I want to calculate the acceleration
acc =  (q.E)/m
I have a very very big number that my application didn't execute it ...
so is there any units that can I apply it in my simulation instead of kg for mass
and coulomb for charge ..
I mean I want to present the  mass and the charge in another units with a different  values ....values that I can apply it in my simulation
i.e : I found that  the mass of the proton is worth 938 Mev/c^2 !!
and this is  a very good number for my application ..
but sure if we want to have a real physics simulation we have to put a right proportion with all units ... 
I hope you understand my question ...if you don't tell me to explain more ...

and thank you again for caring about my question ...