PhD crossroad: dealing with constantly absent supervisor and diverse workload?
It's not clear to me whether you did Step 1 (or Step 2) yet.  Forgive me if you already did them.

Step 1. Talk to your advisor and let her know how much time per week (or a percentage or proportion  of your time) is being spent on the project, and ask for help and/or advice about how to balance your time more effectively.

Step 2.  Work in the library, work at home, but limit the amount of time you spend in your office where other project members can grab you or distract you.