Limit all wedding stuff. Cut yourself off from Pinterest and your planning resources. If you have a personal project that has nothing to do with the wedding, work on that. Or read a book or play a video game or bake muffins or go to a friend's house.
Wine, venting to someone who understands the nature of what you are going through, do a mani/pedi day, do a “safe” facial mask nothing too crazy if you have sensitive skin. All these activities will help you unwind a bit, good luck.
My sister took me to get a facial. A few weeks before our wedding. It was a huge help. Give yourself some time to be pampered. Face masks, manicure, wine, foot bath...whatever it is. Just pamper yourself and get out of the wedding headspace for a couple hours. Good luck, I know it's hard. I found that the closer we got the less stressed I actually got. The week of, I was the calm I'd been the whole time.
Personally, I will remind myself that it doesnt matter as long as I get to marry my FH. Usually it works best if I'm looking into his eyes as I'm reminding myself. I can just get lost in him and that has been the biggest stress relief for me.
Taking a break helps. I didn’t stress much on the planning because I was organized but guest always stress you beyond control so taking a break helps! Some wine, a night out and maybe even a massage or nail and pedi time any you time helps.
I would first question/pinpoint exactly what is stressing you about the wedding and focus on reducing THAT. Then walking, meditating, exercising, getting a massage, etc. can be secondary. Otherwise, the main stressor will still fully exist if it’s not addressed.
This might only MY belief..... but wedding planning is only as hard/stressful as you make it. So often I see self-inflicted wedding stress.
I usually take a day away from planning. I am always looking up something, contacting someone, going over plans, decor, etc, on a daily basis. When I get stressed, I take a day away from it and talk to my FH about it and then he helps and I feel better.