It's not stuck. It's where it needs to be. Using extracts other than Pale/Light/Pils will often mean you end up above where you think your yeast will take you. It's the nature of the ingredients, not the yeast pooping out.
When we more experienced brewers talk about leftover fermentables in the extract, we mean fermentables that your yeast won't be able to metabolize no matter how long you leave it sit or how much yeast you add. Those unfermentables are what makes Amber and Munich extracts what they are; they also mean your FG won't go as low as you may calculate (or your recipe sheet tells you). Yeast can't read, nor can they understand English.
Say it with me: "I will stop worrying. I will leave my beer alone in the fermenter for another 7 days. Then will check the gravity with my hydrometer. If it remains the same (1.020), I will bottle using normal bottling procedure. Then I'll leave the bottles alone for three weeks in a ~70F cool, dark place."
Seriously - you're overthinking this. Do what I tell you and RDWHAHB!