I was hoping after I wrote >>4 OP would provide further details about their situation. As that did not occur, to speak in generalities, I would say making the leap to proof theoretical mathematics would be difficult without feedback (further if one was able to teach themselves these skills, there likely wouldn't have ever been much of a leap to make). Without feedback you're liable to mistakenly believe you are correct and fail to develop the thinking dispositions needed to prove effectively. I suspect there is a similar difficulty in transitioning to research mathematics. Beyond these two leaps it seems to me that mathematical progress is necessarily self directed.