1/ Postmodern philosophy: (re)consider the possibility of pursuing advanced studies in postmodern philosophy, because that is one of the fields where all your bits of knowledge can coagulate and be put at good use. There are academic institutions that can accommodate part-time schedules, or where most teachings are offered in time of the year that facilitate part-time learners;
2/ (Visual) Arts: An art practice can benefit greatly from a solid theoretical foundation of the subject-matter that it tries to address. I am not speaking of arts pursued for the sake of them. I am referring to contemporary art engaging with some of the most pressing socio-political challenges our societies face.
Set aside the fields above, all other fields can benefit from some non-zero degree of interdisciplinarity, but are hardly all encompassing and would leave part of interests less leveraged then others.
I salute you and wish you well.