Just throwing out a thought.... Maybe it's not that you don't have emotions but that you don't have an outlet for them.... When I have no outlet for emotions that are bubbling up... I get overly anxious get muscle tension especially neck..migraines...etc. all the emotions cause physical symptoms for me...

Crying would help release that but I don't do that very often... Kick boxing...punching pillows...screaming into pillows....sometimes helps...

Although it may not be anything like your situation