What Causes Light Pain In The Leg While Walking?

Hi Doctor From last 18 years I am suffereing from very laziness. My eyes are always red and need sleep in entire day despite of 7-8 hrs healthy sleep.My legs have always very light pain and feel very unconfortable while walking. Also feeling very hot and tiredness in the legs. Also My body feels that Iam collapsing.I am a veg and eat normal food. No overeating and take vegetables etc. I am 65 kg weight with 5.4 height and age 20.I usually go 1-2 Km walk in morning and evening.If I run, my legs will have very high pain so could not not run properly.