Just as an aside to all aspiring authors, a blank piece of paper is just that, but it is also other things.
First of all you should not see it as an obstacle to your progress. It is in fact an opportunity. On that blank page will go your words, none of which are new, that you have arranged in such a way as to represent part of your imagination.
Of course it is also a place to try out different word orders. If you're like me editing isn't your favourite sport and so I tend to write, read and re-write, as I'm proceeding. I still have to edit because time is a good barrier between creation and final production as it allows you to come back to a piece and make changes if they are necessary.
I don't totally agree with Anne Lamott, I find that sort of attitude rather negative, but you do have to start somewhere. Irrespective of what type of book you're writing you need to start and that is the initial operation.
My first line in my current novel begins,
“I must admit this is very kind of you "
You could write almost any sentence, or piece of dialogue or description to begin your magnum opus because you can change it if need be.
There are countless writing courses and pieces of advice on how to begin, and there are even flyers like the above that throw ideas at you. I reproduced the one above because it isn't subject dependent but it will allow you to make those first marks on your blank page.
Then of course there is the elephant in the room which tends to be the attitude of significant others to the would-be writer. Until they have a copy of your published work in their hands they won't believe that you are a writer. That is difficult as it may be your parents, your spouse or someone just as important to you. This is the elephant and you can only get rid of it one bite at a time. One nibble could be the completion of your first chapter. It may be 2 or 3 thousand words long so it is significant and as such may give the nay-sayers room for thought. BUT in reality it doesn't matter because if you have the will to write then that is what you will do irrespective of the opinion of others.
Finally, there are those who think that they can criticise you because they were good at English at school. Believe me there are plenty out there. It is similar to people's attitude towards schools and education. They think because they went to school that they know all about it when in fact they know very little. Their logic doesn't stand up to close scrutiny. It is rather like saying that you drive a car therefore you know how they work.
The first sentence on the above is what is inescapably true. Like many processes it doesn't finish when you finish your first novel even if it is published by some world renowned publisher. Try reading someone like Colin Dexter or Ian Rankin. They wrote series of novels within one genre and using the same lead characters. They are good writers but their first efforts are quite raw in comparison to their final works.
So going back to the blank page, don't despair, write that first word or sentence and move forward.