It feels like i have a deep bruise in my thigh. i am a runner, what can i do i am in so much pain. should i stop running?

Yes, you should: If you are in that much pain, stop it and see your doc. It is not normal to have that much pain from running, unless you injured yourself some other way besides running. It could be bursitis, which is not dangerous and can be easily diagnosed, but you should definately check with your doc. Just remember, you can always run again once you know that nothing bad is happening in there. Best of luck.