You really really shouldn't be making those decisions w/o your doctor's knowledge. Your baby feels everything you do, so don't do anything else. Can you make your appt sooner? I wouldn't take online advice about this, and we don't know what's going on in your body. See your obgyn as soon as you can. Good luck to you.
First off, I'm in no way a dr, but I'm a mom who had a baby go through NAS (w/d's) b/c of the meds I was prescribed for my back and I have talked to many MFM (maternal fetal medicine) dr's/high risk OB's and I've talked to many, many women who have been in your, and my, position. Many women have weaned off their meds on their own. If you don't go through w/d's, neither does baby. Same goes for if you do then baby does.
Being that you're 33 weeks, there's pretty much a zero chance of your baby being born with NAS (going through w/d).
I'll send you a private message and direct you to a site that I'm also apart of that only deals with this type of issues. You'll get a better understanding. :)