Paul is, in this terminology, also a prophet. He explicitly says the revelation he tells is not of human origin, and so not passed down to him through e.g. the ministry of one of the students (apostles) of the prophet in question.
It strikes me as unusual to have so much of the theology coming from someone who simply claims private revelation but is not the prophet in question and when the prophet explicitly chose disciples and set a ministry for them.
I am Christian btw, but I support bringing historical and documentary rigor to theology. I also haven't actually doubted anything, at least not of Christ. I've just characterized Paul's gospel and mission as coming from a private and separate revelation, unlike the gospels and missions that the original apostles received.
The point that I made based on that is that it is strange that a lot of the theology of Christianity as it develops centuries later is derived more from the exceptional and privately delivered gospel of Paul, rather than from the gospels of the apostles of Jesus when he also held a historical human form.
I think there is also an obvious scholarly reason for this that doesn't even require belief, which is that Paul's writings are the closest documents we have to the time of historical Jesus. However, that also gives reason for us to be cautious in hanging major theological positions on specific sections in Paul that seem absent from or in tension with the synoptic gospels.
It's interesting that every point of this narrative conflicts with the canonical accounts (even excluding the Pauline corpus for this purpose), in which Paul did encounter Jesus, and did at least spend time with (we aren't explicitly told it was spent in study, but presumably it was not exclusively in silent meditation) with disciples of Jesus between the encounter and conversion experience and the start of his ministry, and he got along as well with the other apostles as the other apostles they did with each other.