I am currently in my final semester of masters. I have some background in Algebraic Number Theory. I have one PhD offer from a US university.
When I started getting into algebraic number theory, I did not have much trouble as most of the pre-requisites were from Galois Theory and Commutative Algebra. But through my study in the last two-three semesters, I have realized that Number Theory is a subject which requires knowledge of many different areas like Complex Analysis, Algebraic Geometry, Topology(subjects which I have not learned properly or not learned at all). This has put me under a quite a lot of stress: Am I good enough to study Number Theory or should I shift to something else, something more self-sufficient?
Is it possible (and advisable) to change my research interest to something else? What should I do?
Edit- To add to my troubles, I don't know anything about Modular Forms or Automorphic Forms or Galois Representations.
Before voting to close this question down, I would like you to know this: I originally asked this question on Math SE. But people told me that it was more of an Academia SE question.