2 then 1

2 or 4, your choice.

2 or 4

Is there a monster therapist? I think the closest one you see would probably be Grillby, but there's also thousands of monsters you don't meet in the game (Mettaton has a lot of fans) so there probably is one somewhere.

Dear Author,
2 or 4 seem to be the best options. Especially if your readers like the content you're producing in this fanfic.
Hope this helps,
Broken~

i wanna know what happens next

II say you work through it and try to write it. Even if it feels like you're slogging through it. You've experienced those moments in writing where the scene seems to write itself, or you find yourself writing more than you ever intend, or perhaps take the story in a direction you hadn't originally planned, right? What seemed boring can, from just a twist of words or a stray idea, become once more reinvigorated.

I suggest thinking a bit more about the story-what you can do to deviate from the canon path and make it feel more your own, giving you more loose places for your imagination to latch onto.

You could write the sequel as a standalone, if you feel you must-but one of the most important parts of any Charisk story is the developing trust and relationship between Chara and Frisk, or lack thereof. Starting off with a sequel skips that. Unless they only start to know one another then, it will detract a lot from their relationship.

Oh hey I got caught up, lack of motivation? Well I vote ya power through it, just stay determined!

Well, I just got here, but if you're asking for advice... I'd say do whatever makes you happy! If you would rather just write the sequel, then you probably can with the inclusion of a few flashbacks or some particularly good exposition. Undertale is nice like that; unless you are planning to change something crucial from the beginning of the game, most people know how the routes play out. Of course, I would love it if you continued also. You portray an interesting relationship between Chara and Frisk, and I like how you made Frisk a teenager. But if you're not happy writing this, don't waste your energy on it. Just because you can doesn't mean you have to, if you know what I mean. :)

I'd like it if you powered through, but if you would rather put it on haitus it is your story.

Please finish i love it

please work through it if you can, im actually really interested in this so far, its completely understandable if you don't, but it would be greatly appreciated if you could.

You could always write the sequel while writing this whenever you want... I've seen a few authors do this and honestly you'd probably finish this eventually even if you abandoned it so yea...

2

While I do want to see were this goes, you don't have to force yourself too keep writing, if your not happy writing it then stop if you are then continue.
Theirs not many fanfics were frisk is disabled even less are realistic so to see one were frisk is weakened from the abuse and is untrusting is rare on its own and too see one were frisk is not naive...
More or less don't force yourself to write something you don't want or like for our sakes your the author write what you want that makes you happy. Thank you for writing have a nice day.