I tried "Holly's Jolly Christmas". It's less than a page with a 4.13 rating and no comments.
You start the story with five paragraphs of narrative summary. Starting a story with a lot of narrative summary is problematic as it is less interesting than dialog. I think it would have been better to have started the story with Amanda and her mom talking. You could have covered in the conversation the same things you covered in the narrative summary, but it would have been more interesting and it would have revealed more about your characters.
I had a lot of problems with the plausibility of your story:
* The mom goes out "paying some bills that she had put off till the last minute". To me, middle-class people don't go somewhere to pay bills. They have autopay or they send a check. And as Amanda's mom was well-enough off to loan Amanda the money to start her business, she's not poor. It's a minor nit, but it starts the cascade
* Why would her mom hide her diary in with Christmas decorations? She'd keep someplace that'd be easy for her to access but where Amanda wouldn't go, like her bedroom or her office
* Why would she think her husband Brad "is an excellent lover" when he can't make her orgasm? That's kind of the definition of an non-excellent lover
* Why is she obsessed with having an orgasm instead of excepting it won't happen and moving on? Moving on is the natural coping mechanism
* Why would she only write about not having an orgasm in her diary? I imagine most diaries are "this is what I did today", "this is what I did today". I could see her mentioning occasionally, "I got a new dildo today. Felt good, but couldn't quite get me there." But not discussing anything else, it's like a color-blind guy having a diary where every day he mentions, "I couldn't see red today."
* Her mom hinting she wanted an orgasm for Christmas wasn't believable
When Amanda decided to eat out her passed-out mom, it just wasn't believable to me. There was no reason for her to believe that she'd be able to give her an orgasm when nothing else could. Many, many other guys had trying eating her to orgasm and failed. Amanda had never given oral sex to a woman. Why cross the line, risking destroying her relationship with her mother given those circumstances?