aches and pains

ok so since saturday the front of my top legs have been killing me (both legs)... 
i feel its definitely muscular pain, but i really have been struggling to walk stairs are the worst! 
it takes ages to get up from sitting down (i spend most of the time brasing myself to get up)i dont think i have done anything different to have caused this pain to appear! 
i really feel like my legs are going to give way when im walking and sometimes not long distances atall.. could it possibly be a trapped nerve? 
It is on the front Not groin area, i feel like ive ran the marathon 😐😕😔