Can Skin Be Permanently Tanned?

I'm 47, female, and very worried about permanent sun damage. I swam outdoors for many years in the summer and my skin appears to have permanent tan lines that have not really diminished since last summer. I always wore sunscreen but by now we all know that that is not enough and that sun avoidance is key. Also, my skin just looks sallow--sort of yellowish tinged--and covered with freckles and brown spots. There is a clear demarcation from where my swimsuit stopped on my upper chest.

I have begun Retin A for my face but I'm wondering if I can also use it on my neck and chest. My neck and chest area just look terrible, weathered and yellowish with brown spots and lines.

If I do complete sun avoidance will my skin eventually lighten in the next year? I do plan to avoid the sun completely except for perhaps very early morning to get enough sun for Vitamin D. Is there anything else I can do to improve my skin tone? I have looked into IPL but I have heard some horror stories. I'm very, very worried.