First of all congradulations on being wise enough to stop using drugs. It must have been a very hard thing to do. Keep it up!
Drug use may lower sperm count, but I don't know if it affects sperm in any other way. The best thing to do is call your doctor or nurse. My gut feeling tells me that the drugs are not passed through the sperm. But I'm not sure.
Why are you sad? How do you feel about being prengnant? How far along are you? Do you have a support system? Please email or post to the message board if you would talk.