"You do know that physics isn't just applied math, right?"
Obviously, or I wouldn't be asking whether it's possible to jump from applied math to physics...
"I am VERY skeptical when someone says 'I learned physics on my own', because it usually means they've read some popular science books about wormholes and fell in love with string theory. MAYBE some of them have actually read actual physics textbooks like Griffiths but almost none have done the problems. If you have not done (or cannot do) problems from an undergraduate physics textbook, you are woefully unprepared for physics grad school. Reading alone does not count as learning in physics anymore than it does in math. Neither is a spectator sport."
It's true that I first got interested in physics when I read pop science, string theory stuff in middle school/high school, but I've since come to really like physics. Only reason I'm saying theoretical physics is where I want to go is because I know I really like math too and I know I'm not extremely experimental. Maybe saying I "realised I like theoretical physics" was a bit of exaggeration. But I do know that I like physics, and that I like the mathematical aspect of it much more than the experimental aspect of it. Most people who choose to go into physics as freshmen have little more than AP level exposure to it (if even that)...why can't I know that I'm interested in it when I have significantly more than AP exposure?
I've done MIT opencourseware for numerous physics classes (physics I, II, and III, right now I've run out of classes with videos so I am trying to use lecture notes + textbooks to fill in the pieces.) with all psets and scored myself on exams if they provided them. I've reviewed all the questions I get wrong on psets and exams and made myself understand them. I am very committed to this. I just don't have any room for it in my course schedule (max 20 credits per semester here, which I've been taking and getting good grades in but they won't let me add more)
EDIT: and I've actually done pretty well on the MIT psets provided on their Open Courseware website. If I understand correctly, these are the problems they are doing at the university. Though this can be attributed to the fact that I was good at AP physics, the stuff in Physics III is wholly uncovered in AP, and I did fine learning that stuff/doing problems.
I understand your skepticism, and it's completely reasonable, considering how many people "think" they are interested in physics. But even if you think I'm wasting my time, can you at least answer whether it's possible to take some physics classes while pursuing, say, a masters in Applied mathematics, then trying to do a theoretical physics program after? I'm really most unsure about the dynamics of grad programs. Nothing you say is going to make me rethink my decision to go into physics. I'll go get a second bachelors if I need to. I want advice on whether this path is easier (but not necessarily a "shortcut," in that a shortcut implies I may miss out on a lot of stuff).