When i reach my arm i get a burning, skin ripping sensation in my left teres major area. ideas? i've had this before on my right side in the same spot

It's a nerve problem: Could be (not is, could be) positional nerve or nerve root entrapment somewhere in your neck or shoulder. The closer it is to the midline and the more symmetrical it is, the closer it is to your cervical spine. More likely in people who are very thin, very muscular, or have some cervical degenerative changes. Don't rush off to get it fixed, but do see a doc if you desire reassurance.