Rash on face and headaches

I had a car crash 3 weeks ago which though not severe resulted in a lingering headache for 5 days. I went to A and E but they told me it was a 14 hour wait and that due to my headaches intermittence I should rest up and call if it carried on. I went to the docs one week ago as little things keep triggering it such as laying in the bath and waking up but was told it was stress and anxiety which I was fine with as I do have terrible HA and generally notice the littlest thing. I went to a shop changing room today and discovered a rash all over my face though, its not easily seen and I have good skin but its like little red spots all over my cheeks and blotchy and Im obviously wondering what this could be - I had the lingering headache last night despite drinking water but it came on after I had a bath (this has been my recent trigger). Whats going on here? should I go back to the docs? I must confess I feel fine otherwise