Gah, sometimes I just want to give up!

I am 42 and haven't had a tan in 21 years (not since my dad was diagnosed with melanoma in his early 40s). I have very fair skin and suffered many horrible burns when I tried to tan as a teen, including some blistering burns from spring skiing. Given the damage I undoubtedly suffered, my pigmentation problems aren't that bad--I have some faint freckling and a couple of small spots (size of a pencil lead) (not melasma). I've had some laser treatment and really have only a few spots left, which I've been treating with HQ. Between the treatments and my regular use of sunscreen, I feel like I've made a lot of progress in the last two years in getting rid of the "freckles."

But, after some outdoor activities this spring (generously covered with MAC prep + prime or Clinique Super City Block plus a hat and sometimes with JI foundation on top) I have some new "freckles"!!

What causes this? If I were locked in a windowless cell for the rest of my life and never saw the sun again, would my prior sun damage still come to the surface? Or is it the new sun exposure?