Welcome to HCM,
Your aunt is suffering from Diabetes
and if you do not take care for long term now most likely she has developed Nephropathy and Renal failure
In early stages of kidney failure medicine work and condition can be controlled but as you say her blood urea is rising rapidly and Haemoglobin
is also low ,I am sure her urine out put is also reduced hence waste products are not filtered.
She will require emergency Hemodialysis
to rescue her from renal failure, she has no other choice now otherwise her condition may worsen.
She also need to take care of her blood sugar level as well as correction of anaemia, Please consult a Nephrologist
as soon as possible.