Hi, is your blood pressure reading actually low, as this would certainly cause those feelings, I have had and still have bouts of dizziness, although I've had various tests and I do have the following high blood pressure, stage one hypertension not enough for meds, and b12 deficiency which I now have b12 injections for done at gp surgery, anxiety which I've took various antidepressants for over the last 12 years, hrt for menopause, but I still continue to get these scary bouts of dizziness which affects me going out, for me personally I think it's a combination of anxiety and hormones, when you said when you walk in a shop and the feeling is not going away and your legs feel weak, that's exactly how I used to feel and still do at times and I was able to pinpoint that situation to anxiety, I think it would be wise to get a blood test to rule out any deficiencies, and mointer your BP, but try not to worry that this is something awful, as that will feed anxiety and make it worse this happened to me and I feared the feeling so much I seemed to almost induce it to happen, for me personally after many tests and being treated for things they did find I still have the dizziness so it's almost for sure down to hormones and anxiety for me, changing hrt might be worth it too, I'm on estrogel have been 7 months but I'm suffering more dizziness on this than on patches so thinking that's causing a problem for me, it's difficult to figure out and I feel for you hope you find some relief x