Is there such a thing as "too damaged" when talking of a baby? Isn't any "damage" too much? If you take in poisons be guaranteed that this is harmful for an innocent fetus.
You need to see your OB and talk with them about this. How far along are you?
I second the above advice, all of it. You need to talk with your OB, and right away.
Please read this, meth use during pregnancy is nothing to mess around with:
http://www.webmd.com/baby/news/20050727/1-hit-of-meth-is-too-much-in-pregnancy
Best of luck to you, I hope you get the help you need, and soon.