It depends very much on your own skills and drive.
At some point, you need people to check your work, though, but you can search for online communities to do that. E.g. a post to mathoverflow asking about whether the following proof is correct, for example. Try to find a community of others online and work with them.
Also remember that math is about ideas. It is not just an exercise in formal deduction. The field is dense with non-trivial, non-obvious, interesting insights, and understanding these insights so well that overtime they become obvious to you is what it means to learn math. Sites like 3Blue1Brown to a good job trying to explain these ideas, but they really put a lot of work into it. Most math texts do not, but you have a professor or classmate you can talk to -- so there is a gap between the text and what you need, but perhaps you can close the gap with online resources.
At some point, you need people to check your work, though, but you can search for online communities to do that. E.g. a post to mathoverflow asking about whether the following proof is correct, for example. Try to find a community of others online and work with them.
Also remember that math is about ideas. It is not just an exercise in formal deduction. The field is dense with non-trivial, non-obvious, interesting insights, and understanding these insights so well that overtime they become obvious to you is what it means to learn math. Sites like 3Blue1Brown to a good job trying to explain these ideas, but they really put a lot of work into it. Most math texts do not, but you have a professor or classmate you can talk to -- so there is a gap between the text and what you need, but perhaps you can close the gap with online resources.