The combination of blood and protein with back pain
is highly suggestive of stone in urinary tract
. There could also be have been urinary infection - Antibiotic helps in infection not stone
The best solution will be to have investigations - kidney function tests / X-ray +/- Sonography
of kidney-ureter- bladder regions....
will be the best person to approach
In the mean time, anti-spasmodic and Non-Steroidal-Anti-Inflammatory-Drugs (NSAID) will help for symptomatic relief
Wishing you speedy recovery