hello all, its been a little while...but i can never stay away!!!

anyways, my question this time is...

I know that I always favor sleeping on my left side, and yes i sleep with my arm under my pillow... i really try and correct this and switch to my back or my other side but its not all that easy to do! Any ways, ive noticed this deep burning sensation in my upper arm during the day if i lean on it for a little bit and it just does not go away. It comes and goes and i can not tell you what makes it come and go nor do i notice it right away! has anyone else had this? have any tricks to help it ? it stupidly really triggers my anxiey alot and it I just can NOT have another stinking trigger!!!!! thanks so much!!