^That's good that you've stopped DXM use. Pseudoephedrine is still a stimulant, although it is much weaker than say, (dextro)amphetamine or even regular ephedrine. Of course these stimulants have their side effects as well.
Ephedrine and pseudoephedrine are vary "dirty" feeling for some people (myself included) but if it's working for you than it's working for you. Amphetamines such as Adderall and Dexedrine that are used for ADD are much "cleaner" feeling (meaning less side effects), although that is subjective to say the least.
For people with ADD, amphetamines can decrease anxiety, as they help focus and attention...but for other people, amphetamines usually increase anxiety.
Be honest with your doctor, everybody is different but if you work with him/her and explore your treatment options, you will find what works for you.
Benzos can be hit-or-miss, but they are a good option for many people, barring the problems with addiction/dependence that they're so famous for. I personally think everybody who uses/has a prescription for amphetamine-like stimulants should be given at least a few benzos in case of a panic attack, anxiety and things of that nature.
Again, props for stopping use of DXM, long term usage of high doses fried a few of my good friends' brains in high school when tripping on DXM was all the rage. It's powerful stuff and I don't touch it anymore for that reason alone.
Best of luck man, and I hope everything works out well for you