ok check out the bottle and see if it has a breakdown showing mineral content. that's one thing that could be telling. for another, you can potentially look up your city's tap water to see what that mineral content is. look for magnesium and potassium in particular, but sodium and calcium too. the prior activity level could have had a depleting effect and the water might not be up to the job of replenishing. most sports drinks don't quite get you there for replacing lost minerals either - too much emphasis on sodium and potassium.
Comparison of the Mineral Content of Tap Water and Bottled Watershttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC1495189/
..... Table 2 - Mineral Content of Tap Water in Major North American Cities (mg/L)
..... http://www.ncbi.nlm.nih.gov/pmc/article ... able/tbl2/
..... Table 4 - Mineral Content of Selected Commercially Available European Bottled Waters (mg/L)
..... http://www.ncbi.nlm.nih.gov/pmc/article ... able/tbl4/
Variation in the mineral content of commercially available bottled waters: implications for health and diseasehttp://www.ncbi.nlm.nih.gov/pubmed/9727819
bread contributes to depletion of a number of nutrients. some others may be lost during processing (eg iron, b vitamins - what you see added to enriched flour). if you eat a fair amount of bread, you might want to consider compensating for possible loss of minerals. i'll try to track down some studies but for now, i'll just say that iron, zinc, and magnesium should likely be on your radar. low mag will have particular relevance where headaches are concerned. and low zinc where potential allergy issues are concerned.
since you are currently symptomatic, you could try working on getting 600mg of mag daily from healthy foods, http://www.whfoods.com/genpage.php?tnam ... #foodchart
and minimizing bread intake as well as coffee, alcohol, or other diuretics that could promote loss.
you could also try a magnesium supplement. not all are created equal - i would not necessarily recommend 600mg of mag oxide unless you like your bathroom, a LOT.
you'd be ok with mag oxide if you only needed to top up from food a *little*, to reach 600. if you need more supplemental mag, look for magnesium glycinate, like this (it will be in a specialty store not the average drug store): http://orangenaturals.com/essential/mag ... g_60v_cap/
none of this will do you any harm while you sort things out with the doc. it's just essential nutrients, and low levels can result in symptoms. best to get rid of those possible aspects so you have a clear picture of what is left, to present to your docs.