Had this problem for years, and it's not pleasant at all. In my case, I get a stiff neck - this can lead to dizziness. The worst part is my stomach muscles contract - and this eventually leads to sickness
This is the old story that you "worry yourself sick" - literally.
How do I cope - well, I had some real problems with this some years ago, and was on medication, and had to see an psychoanalyst. Things got better though
Nowadays, I just learn to read what my body is saying, I do relaxation exercises - and above all, having friends I can chat to, and with whom we share our problems as well as joys helps.