Hello Welcome to health care magic Dear patient, as you are taking anti histaminic/decogestants on regular basis, it indicates that you have chronic allergic rhinitis/rhinosinusitis which at times may be becoming exaggergated/secondarily infected to cause stuffy nose and stuffy nose gives rise to altered taste and smell as well as leading to oral breathing that causes dry mouth and desire to drink more water and dry mouth further exaggerates metalic taste. your urine may be smelling normally but you are perceiving stronger smell due to altered sense of smell . Now you need not to worry but just consult an ENT surgeon who after examining you will prescribe you some necessary nasal decongestants and antibiotics and hopefully you will be fine. You can also try stam inhalation two three times daily wish you speedy recovery thanks Dr Arshad