Write about the last time you did something that scared the crap out of you. This could mean opening an intimidating envelope from the IRS, sending an email you dreaded writing, getting a spider out of your house, confronting someone, getting a shot, whatever. It doesn’t have to be the biggest thing that ever scared you, just the most recent one.
If you can’t think of anything that has scared you lately, write about that.
Write until you surpass memoir-mode and start to layer in a narrative voice in service to the reader.