i have read about your problem of voimiting blood . blood is not normally seen in vomit with out any underlying problem like ulcers.as your endoscopy
is normal that means you had a mild tear in the mucosa which can produce blood in forceful vomitings or when try to hold the vomiting. regarding your pain,burning urine and urgency to urine is because of urinary tract infection
secondary to stones somestimes are not visible in tests(radiolucent) .please contact your physician,who can prescribe antibiotics.
i hpoe this will help you
take care ,have a good day