When working with muscular pain, everyone is individual, so I cannot say how quickly your particular changes will happen. However, I will give you my best estimate for how many sessions based on similar client situations.
Please note: By law, a massage therapist cannot diagnose or give prognoses for any disease or pain syndrome.
As for general relaxation massage, I suggest you come as often as you feel you need and/or want to. But the great general rule of thumb is once a month. Consider it a time for your body to get its monthly tune-up.