What Causes Burning Pain And Tingling In The Leg?

I am 70 yrs old, 5 7, 9st.have had very little health problems at 65 yrs old had Chrons disease. In control with ASACOL Tablets, APRIL this yr had tingling down left side, burning pain down left leg,below knee and under eye, cheekbone, Saw doctor twice about , He didnt take any notice, Went to local Hospital , they said SHINGLES, this is 3 months later gave tablets , I took them all but the burning pain still there. I am at my wits end. Friends trying to help , told me to use EURAK ,It helps a bit, but the pain for 4 months now is getting me down Please help me.. I did not get a rash until later and now it is so painful .