When I get to a high pain level I get nauseas as well. I try to keep saltines on hand it seems to help me. I have been told that bp increases for some too. Also some meds do this. I know sometimes when the pain gets so high I feel similar like I don't know what to do cause it seems endless and out of control. I agree with the deep breathing. Also what other things may bring you comfort. It sounds dumb but for me even this soft blanket helps. Sometimes listening to music. Baths for me help too.I'm not sure where your rsd area is but for me sometimes moving or adjusting my body helps. Sometimes not but if I have been in one position too long my pain increases so moving helps but it is doing it which is less then pleasurable. Lastly self talk I remind myself I have had times like this before and I got through. If you want an email buddy I am here too. The many good friends I have met through here help so much. Hang in there and take one day at a time or even one hour