I currently take 45mg buspar, (buspirone) doc wants me to switch to 22.5mg buspar (buspirone) and 2.5 mg lexapro. is that a good start, i am hypersensitive to meds and scared.?

Good start: It sounds like you are being treated for an anxiety disorder. Both drugs are approved for this diagnosis. Since you have demonstrated some sensitivity to medications your physician is being cautious and starting at low doses. Be sure to give your health care provider feedback on how you are doing so that the doses can be adjusted upward or downward if needed.

Good plan: This sounds like a good start to what your doctor probably has planned. Because you are very sensitive to med changes, it is a good idea to go slowly with your transition.