What Causes Headache After Having Lumbar Puncture?

I had spinal tap (lumber puncture) procedure done and within 24 hours I developed intense dull like head splitting headache (I thought I was dying) I found an immediate relief by simply laying down.I went to ER then was diagnosed with spinal headache (post lumbar puncture headache) anesthesiologist performed a blood patch and gave me a relief then discharged from ER. Within 4 hours later splitting headache returned and waited for few days and I gave in and returned to ER (My neck pain developed during last past few days). Anesthesiologist gave me another blood patch and headache finally subsided, but not for my neck pain. I m still struggling with neck pain for 3 weeks. Any insight on it or what should I do?