IMO you will probably want a massage therapist over a chiro.
Call around and find a MT who is skilled in myofascial and cross-friction tissue work - preferably one who's been doing it for a while and has experience and good, strong hands.
Posture & tensing up can often lead to trigger point development.
Chiropractic adjustments may help correct some posture problems, but for direct tissue work, it’s hard to beat a good massage.
OMT – it may benefit you to examine your work station. Are your computer monitor & keyboard positioned at the correct heights?
A lumbar support may help with your chair.
There’s a term for the above practice, but the name escapes me.
If interested, just do a web search for details on arranging office desks for optimum posture & comfort.