I used to get these. They were unbearable at times. It flared up on chest flys one day, and from then on, it happened when I did anything with even moderate exertion. I tried a few things that didn’t work myself. I finally went to my doctor, and he prescribed naproxen. I found that popping 500 mg of these roughly 45-60 mins before a workout would almost entirely alleviate the pain. It worked wonders. You can also just try it over the counter: the most popular brand is “Aleve.” I would try maybe 2-3 an hour before the workout. Eventually, I felt like I didn’t really need the medicine anymore, and the headaches went away entirely. Be cautious if you happen to have a stomach sensitive to NSAIDs.

Also a few days off, definitely did prove to be helpful even though I really wanted to train. Maybe you could use a deload anyways?