I can see the videos - she's definitely not right. When a piggy doesn't want to eat she doesn't try but poor Biscuit wants to eat, and to be honest it looks like she is wincing either with pain or effort - if you see the little squint she does with her eye in the first video. Her chewing is slow though, and very erratic, and the way she paws at her mouth is letting you know something is bothering her - it might well be a bit of stuck food but I wouldn't like to make that assumption as she was already having problems before the dental.
Are you certain the vet didn't do anything to the molars? Would it be worth checking..?
My rainbow girl Ivy was syringe fed for some weeks. Her problem remained a mystery but one day she just let a nugget drop from her mouth and turned away. Her molars were slightly overgrown at that point so she had a dental and about a week of antibiotics and painkiller (as standard, but the ABs were also to try and address whether there was some mystery infection that had stopped her eating in the first place). The vet adjusted the molars but left the incisors which were OK at that point. A few weeks later I had to take her in again for the incisors to be burred... as it turned out a bit too short but nevertheless, when the overgrown incisors were out of the way her chewing (of the syringe slurry) became immediately faster and smoother. Incisors are for biting and manipulating the food into the mouth, not really for chewing so if she had incisors trimmed but the molars were not touched you'd expect there to be improved chewing or at least the same as before. It would explain why she can't get little bits of food in, but not why her chewing isn't smooth. Maybe try offering longer matchsticks of food so you can support one end which she champs at the other? When Zara's tooth played up I gave her a plate of little bits from the middle of cucumber and she was able to slurp these up without biting with her painful incisor. It's not nutrition, but it was hydration and made her feel a bit better about life.
NB: check she is still using a drinking bottle - if it hurts to get veggies in, the metal spout might be too painful. Perhaps offer a water bowl too in the short term?
If she pawed at her mouth before the dental it could be part of her original problem - be it an abscess, or tooth spur, or stuck food, or something else. If this pawing started after I'd be concerned that perhaps a tooth had been hurt by the clipping; maybe not split but perhaps pulled at or damaged in some way. Perhaps a rough edge is chafing her soft tissue as she chews. It sounds like you have your hands full on Friday but I wonder if you could make a vet appointment and either rope a friend/partner in to take her or arrange to drop Biscuit there in a carrier? If you explain your situation they might be able to make a suggestion. They should have the facility to put her in a little cage until it's her turn to be seen - they house animals for surgery etc. You could call and enquire about cost - I think my vet charges about £12 for 'day boarding'. Just a thought. I'm so sorry it's all happened at once for you x