left hip pain (maybe due to prolonged sitting)

[HASINGH]

I am having a severe pain in my left hip. The pain goes down to my thigh and left calf.
i can pinpoint the pain location by pressing the right area. Its on the outer side of hip just below the hip area. Almost near to the place where they put needle for injection.

I have suffered this problem 4-5 years back and at that time the physitherapist I consulted said that the pain is due to muscle stiffness. the pain disappears or gets almost to zero after stretching exercise.

I went to gym and did treadmil (walking only)and cross trainer for 20 minutes each and the leg was absolutely fine. but once i came back home, I started to feel the pain slowly and after sometime it increased.
The pain becomes unbearable during office hours as I need to sit on chair. Though I go and try to stretch my legs after an hour or so, but still its very painful to spend whole day.

A painful sensation goes down to my leg from hip whenever i stand up from sitting position. Its painful to bend and put on socks, to pick something from floor. I am very frustrated from all this.
Can you pls suggest remedies or anything that can help me bringing myself back to normal ?

[Caryopteris]

It is probably a tight psoas or iliopsoas muscle.  It is from too much sitting or using muscles in an imbalanced way.  

[HASINGH]

An update on few things on this...
I've been doing stretchings everyday and now the pain has come down to a great extent.
I dont get a painful sensation whenever i stand up from a sitting posture.
Plus there is no pain in lower back now.

I am having a mild pain only in the hip area and that too when I sit on chair for about an hour or wake up in morning. It feels like my hip has been squeezed tightly.
This feeling goes if I take a walk or stretch for few minutes.

I have stopped weight training after this, now since there is no pain in my lower back, can i start with weight training ??
If there are some other suggestions, please tell. It is very horrifying experience and i never want this happen to me again ever.