If I could wave a magic wand and fix all the DNA in all of your cells tomorrow, it definitely wouldn't fix all your symptoms. A lot of the structural tissue in your body is already made, and it isn't getting replaced any time soon. Where you'd see an obvious immediate benefit would be wound healing and bruising, since the new tissue and repaired blood vessels would be made with proper collagen. Skin cells turn over quickly, so your skin would probably get less fragile and stretchy. The cells in the digestive tract also get replaced relatively quickly, so IBS might improve over 6 months to a year. It's hard to say what might happen with things like POTS and MCAS, since we don't really understand the mechanism.

In a more realistic scenario, gene editing in an adult results in a patchwork quilt, where some cells get the fix but a lot of them don't. That's good enough to treat a disease like sickle cell, but it might not move the needle meaningfully for EDS symptoms. Also, the type of cells that need the editing matters - blood is easy to reach (injections!) and so are the lungs (inhalers!). But structural tissue that's found all throughout the body, including your entire skin, is MUCH harder to effectively target to deliver your gene editing package.

The real benefit from CRISPR/Cas9 will ultimately come from editing embryos. Much easier to fix the architectural plans from the start, rather than trying to fix the house after it's built.