Have you read the Double Degree Dilemma essay closer to the top of this music forum? Since you already have 40 credits, chances are the BA is the best degree for you. Are you considering a state school? Do you qualify for financial aid or merit at a private school?
Have you had classes or a teacher for composition? Have you had performances? Any summer programs? These are all things to consider if you are going to combine music theory and composition.
Try to avoid loans.
For master’s, if finances are an issue, as they should be with this goal, focus on schools that provide funding for both master’s and doctoral degrees, usually with the master’s part of the doctoral program.
Do you envision an MA or MM, PhD or DMA?
Selective doctoral programs accept students from all kinds of schools and backgrounds. The crucial part of the application is the 3-4 pieces you submit. Resume of performances and connections made at summer programs help too.
Declining enrollments, particularly in the arts and humanities but also due to demographics, were already making stable jobs difficult to get in music, and COVID has made things exponentially worse, and things may take awhile to come back.
People who cannot imagine doing anything else do continue on this path. But proceed with eyes open. You can teach as an adjunct or instructor, look at jobs in secondary schools, or have a day job. Be realistic, but don’t be discouraged if this is what you really want to do.
The suggestion to date people with good incomes was made in jest, and I have heard that joke in various forms for years in the academic music community.