Help! Back pain, leg pain!

Not baby related but these issues have occurred after having baby. I have tingling in my upper back, lower back pain. And now tightness in my right leg, sometimes tingly...a feeling like it's swollen but when I look it's not. Anxiety makes me think the worst of things. My doctor won't give me a referral for an MRI and tells me to exercise. I've been doing so for 2 months and seems to get worse. Don't know what to do anymore.