What Causes Tingling In Legs And Numbness In Feet?

Hello, I am a 23 year old female. I'd like to think that my problem is all in my head, but here goes. I stand on my feet for long periods of time due to my career. I have always had that tingly feeling in my feet after work, but I assumed it was because they were tired. Then it became more frequent. At night I would have to wiggle them around because I couldn't keep them still; the feeling is hard to explain. Then, about 2 years ago I was in a car accident and I banged my left hip very hard. Presently, my left knee has been hurting when I go up stairs, my legs tingle often but mostly my left, my feet turn numb rarely and occasionally sharp pains occur in my leg only (they don't shoot down from my lower back or thighs). Should I just exercise more often? I don't have medical so I'm scared to spend the money if it's not a real issue.