Can I mention this? I'm scared to join the army. It's mandatory in my country and I feel like a coward for thinking I'm pressured to risk my life.
Really? I am not sure I get that. Why are you scared to join the army and fight for your country?
If the enemy kills me, it will be bad for my family.
While I can relate not wanting to do things that endanger your life, you are still obligated to fulfill the service. It is the law and you have to follow the law no matter what or you can be jailed, disgraced, or exiled.
I'm not signing it.
If you don't sign then you will be also harming your family by your actions. It looks like you are doomed either way, but be assured it is better to face it head on and be brave. People won't think of you as a coward then.