You just have to find what works for you. I have found yoga enormously helpful and the weekly class has really helped me to get through some very tough times. I find it really calms and relaxes my mind and body: i do iyengar yoga. Also find 5 mins meditation/ self hypnosis in the morn helpful. But different strokes for different folks.
Exercise... that's what I'd do. No idea how fit you are, but suggest you get yourself plugged into some good music and go and walk by yourself outside in the fresh air. Leave semi absent DH to hold the fort for a bit.
OK semi absent hubby-works away during week, golf mad at weekends, 3DSs all lovely 2 with SEN ages 13-17, stressful job, also doing more and more work for a mental health charity (ironic I know). I am stressed beyond my normal tolerance- last night sat weeping and wondering if i could get a chill pill from the GP, need to get outside my own head.