That's a tough one. Several years ago, I took Chemistry during the summer session. 5 hours a day, 5 days a week for 6 weeks. Lecture AND lab daily. Seriously, it was my job. I had no time to do anything else. I was in school from 0800 to 1300 daily, then came home and studied that days material then read the next days material... it was exhausting. It was well worth it because I finished it in 6 weeks and will thankfully never have to do that again. This is just me, but if I had had to work a job and take another class at the same time, I would have been toast.
I truthfully believe that A&P is important enough to devote all of your available time for. Your chances for success are definitely improved. However, you're the only one who can make that decision. I know that whatever you decide will be the right one for you. And again, I wish you much luck and success in school and in your career!