I think this something that needs to be checked out by a doc,it could be something minor but doesnt sound like a typical anxiety reaction to me.Lily
Also, the trauma can be almost anything...punching something, hitting a ball, banging your arm on something, pounding something, and several things you would never suspect could cause a lymph node to swell. Usually it's nothing.
The diarrhea can very well be stress related. Not sure about the armpit pain. It can be a swollen lymph node, which can be caused by trauma, a cut, a virus, or damn near anything. I had a swollen lymph node with pain in my right armpit that I was so convinced was a tumor I drove my doctors nuts until they referred me to a specialist. My anxiety was so intense they finally agreed to remove it surgically. It turned out to be nothing.
Typically if you have fevers and night sweats that's an indication to get it checked by a doctor. Doesn't mean the worst, but it's better to have peace of mind and let a professional have a look.
BTW, when I first noticed the swollen node my family practice doctor wanted me to wait 30 days to see if the swelling or pain went down. There was no way I could wait that long, I was a wreck. In hindsight, I shoud have waited, I could have spared myself unnecessary surgery.