my immigrant visa going to expire before i can travel and enter usa what can i do before it being expired?

after filling the petition by my dad and i recieved my immigrant visa , my country can't let me travel before i apply to the mandatory military service and see if i am fit or not and then i can travel and it will take a long time so my visa will expire before i can enter USA so please can anyone what can i do in this case?

Get an attorney. You have a difficult problem to sove. A good immigration attorney may be able to help you. If you do nothing your visa will expire and you will have to start the whole process again.

go to ambassy

There's nothing you can do. The visa must be used by the date it expires. If you don't use it you must start the entire immigration process all over again and that will take years.

Go to the embassy in your country and tell them your situation and see if they can extend the permitted time to travel. There should not be a problem if it is for an I 130 application since this is a number based on your father's application for you. Either that or you can sneak out of your country and travel from there, since you have a valid visa for immigration here, there is nothing they can do once you leave.