Vaginal pain may be due to dryness of the vaginal skin, which occurs due to post-menopausal hormonal alterations. Another cause of dry skin is diabetes, though I do not know whether this affects the lining of vagina as well. You mentioned obesity, why not try to decrease both weight and fatty tissue, believe me, that also controls diabetes. I know its easier said than done but one can always try a combination of diet(no oily/fried foods, more of natural vegetables,NO junk food/pizza) and exercise(walks,simple basic stretches, cycling, if possible). Oestrogen creams can help, also painkillers like tramadol.