What dose are you taking off the clonodine?
What dose of oxy are you jumping off?
These are a couple really important pieces of background info needed to even start answering. Of course negative reactions to a medication is something that would cause anxiety. Although going through opiate withdrawals will definitely be what's causing your anxiety. Get some good stoney weed like og, Hindu, or Afghan kush for the physical discomfort then get a THCV heavy strain when the anxiety becomes much to go with it like Jack the ripper and I assume the classic J. Herrer is high in this alkaloid too as is Durban poison. I'd recommend getting bud of whichever kush and hash if you can and just the hash for the THCV heavy strain.