If you are feeling suicidal then you need to get help asap.You can go to the emergancy room,or call the crisis hotline to get you through the night.
Post on the addiction forum for more help and suggestions on getting off the dope, there is a lot of experience on that site
Addiction is ugly and yes it will cause us to loose everything that matters.
You and your children and your parents will be in my prayers.
You may find a lot of help from others going through similar on the Addictions Forum,Have you had any counseling help to be able to quit using the drugs? it is possible you need that outside help as it cant be an easy thing to do by your self.You could give it another go as once you are freee you will be able to be with your family, if you want to do it there will be help out there for you.,I know its not easy ,good luck