Back ache that spreead till the feet(sole)

Towards the end of October 2011, i started having slight lower back pain. I thought it was minor and ignored it till it got really worse by November. I couldn't move and lying down on the bed straight was even more painful. By Mid November  i was diagnosed with urinary infection. At the time there was slight rectal bleeding as well. I got treated for urinary infection and the bleeding stopped by itself. However, some of the painkillers were working and i was able to go to office and all. However, there was a very obvious involuntary limp while walking. In December one fine day, it started aching so badly that if i had to walk i had to bend backwards. the pain originated in the lower back and it spread to my right leg till the soul. As instructed by an Ortho, i took an MRI and he diagnosed a slight disc bulge and something else called Sacralolitis(i think). After two weeks of bed rest i was able to start walking again. However, i am still not free of pain. Its the same though not bothering as much as before. A month ago, one fine day i realised that there is a stone in my urinary tract(Unbearable pain). Did CT scan (4mm stone) and took medications. Now, one of my ears is blocked and i am unable to stand or move. I feel dizzy and nauseous. The back pain is still the same. I did gain around 10 to 12 kg in a year between 2010 and 2011 November. I am25 years old,  5 '7" tall and 70 kgs now. Did tests for TB, etc and all normal. Had Primary complex when i was 2 years old but got treated and was cured. I am still worried about this pain. I am unable to run or jump like before.  The way i walk now have made the sole of my left shoes/slippers get thinner and thinner. Please advise and help. I have seen 18 to 20 different doctors in the past 6 months and also quit my job. Please help me.