Friends please help me out Frequent urination,yellow urine,depressed

I am 23 yr old male,i have completed my engg.and for the past few months..to b precise from 8th august ,2009,am having some urinary problems,it all started with lower left back cramps,then constipation,and afterwards to frequent urination.I consulted a urologist and he
advised Ultra sonogram of abdomen,urinalysis,and abs X-ray.
The Urinalysis report was normal,eith no albumin,no sugar,pus cells-1-2hpf.
USG showed raised cortical echogenicity of Kidneys,small speck of calcification in kidneys.
Bladder was well distented with 700cc of urine before urination but 65cc remained after urinating.
If i do not urinate within 3 hours,then it leads to yellowish urine.If i continue drinking  water,then urine is normal,otherwise it gadually turns to yellow and my mouth becomes dry.
I had to change my sleeping posture too.
Earlier i used to sleep on my chest but after these symptoms started am forced to sleep on my backside.
I am extremely deppressed,and am constantly under the fear of death and feeling very anxious about my health.
I sincerely request all of you to please diagonose my conditions and advice some effective remedy.

[jimgreg]

ive got the same issues on the times mine turns.. mine if when i get up its dark like it should be,,cuz when the kidney gets down to 15% of fluids it keeps it filtering  with the GFR..so by morning you flush the kidneys out with fresh water..toxins build over night.,.but if i were to drink water all day its clear,,then 3 hrs later wile the water is still in my system its darker until i drink more water then its tinge in color..i had urine tests came out all negative..i drank 72 Oz's today put 40 out..and urine darker..with less volume like 2 Oz's..but when i get up am i pee 2 times 16 Oz's  total..go figre......its the way our kidneys are designed..i only have 1