Overly Sensitive Neck or Aggravated Something Training Triceps?

I experienced a neck sprain a few months ago and recently started doing PT for it a couple months ago in May. The other day my Dr. ok’d me for the gym but said to “know my limits.” I definitely still feel the spraine but he said the gym is good for me so I went yesterday. I tried a tricep exercise and felt something become aggravate. I did not feel any pain at the time or now (the next day) but it doesn’t feel like it did before, it’s kind of an overly stretched feeling. It was annoying because I didn’t even have any weight on the machine I was using (tricep cable push down) I just wanted to see if I could do it. Is this a case where I’m making something out of nothing (which I tend to do) or did I actually make it worse?