Suggest Treatment For Soreness And Pain Across Neck And Back

I was in a car accident yesterday morning i am extremely sore across chest neck and back. I went to care now last night There were no rays and he said he didn t feel any broken bones. Today is worse it hurts to cough chuckle or sneeze. I used a heating pad last night woke up fine this morning however i used it again today after using it i noticed red streaks on certain parts of my stomach (not all over stomach) and some on my breast is this from the heating pad? Its now Bern 4 hours since i used it and they are still there.