I am glad that you have discovered therapeutic massage and that you are finding it to be helpful. Massage therapists are specially trained to work with you to identify areas of tension and soreness and help work those out. Specially trained therapists may also have skill in dealing with certain types of chronic medical conditions and chronic pain conditions.
The benefits of massage mostly stem from the ways in which they help the body relax and how they help you achieve a sense of well being. These feelings modify how your body perceives pain and stress, leading to a relief of these symptoms.
There is no particular frequency with which you can have a massage. Deep or vigorous massage work should likely not be performed too frequently, as it can lead to soreness itself. However light, gentle massage could be in theory performed as often as you like. There should not be an medical reason that would prevent you from having that type of massage work done quite frequently. For most people, the primary issue here is cost.
Talk to your doctor
for more questions about massage therapy and other forms of alternative medical therapy, and talk with your massage therapist
to figure out how often they are available to work with you.