What type of specialist would I see? No one knows where to refer me

What you are describing sounds like
Axillary web syndrome or cording. It is thought to be an inflammatory reaction
to connective tissue from the trauma of surgery. Fortunately, it is a
self-limiting process that resolves in a matter of months. In the meanwhile,
you should have a referral to physical therapist to help maintain range of
motion in the shoulder, ease the pain and help resolve the process. See attached web
reference for more details. Good luck and thanks for sharing.

scar is in three dimensions--- it is not just a surface phenomenon. the scar is pulling perpendicular to the skin and in doing so, it is bow-stringing some bands that go to your lateral chest as well as your upper  arm.This is not unusual and I have seen this several times after axillary breast augmentation. In all cases, this completely resolves over time. I would recommend that you not do anything to this for at least 12 to 18 months because any intervention will simply reset the clock and create new scar tissue. After that time if you have residual problems I think fact grafting would be an option but I don't think it will be necessary in your case.Best regards!!

It appears that you have an axillary scar.  Please give more information to explain.Here is a general comment that may or may not apply to you depending on your surgery: Axillary bands like yours occur occasionally following axillary breast augmentation and other axillary procedures.  They resolve with time and range of motion exercises. Such bands can be released surgically, but it is usually not necessary.Best wishes, Dr. Connall