Exactly, benzodiazepines are definitely more harmful and baby can actually become addicted. There are meds such as propanalol or vistaral for anxiety that aren't addictive. However they definitely aren't exactly as fast acting and idk how safe those are for baby either so definitely talk to your doctor.
I would talk to your doctor some more. If you need it, then you should take it. Maybe ask him if there's better times than others to take it, to minimize how much gets to the baby.
I would advise against it bc it does cross the breast milk. However if your doctor thinks the benefits outweigh the risks and you really feel you need it then it's up to you. You can always talk to your doctor about other medications that aren't as severe. I'm actually suppose to be on medication but I am not atm bc of the pregnancy and have decided to formula feed so I can go back on them. Good luck hun, it'll all work out, just talk to your doc.