How to sort this paint situation

[RiotC]

So I painted this wall, am very new to decorating things. I used frog tape to do a neat line and it pulled all the paint off the ceiling. I tried to repaint and it looked lumpy and gross. People tell me it's because there was no mist coat originally on the wall (before I moved in).
So I've sanded a bit and cleaned it with a damp cloth, once it's dry if I just repaint the white is it going to look ok?
Is there anything else I should do?
Want it to look nice for Christmas!

I think the best you can do is what you’re proposing. You’ll have to do a couple of coats of paint on the ceiling to match what’s already there. Take care to get a straight line where it joins the wall then feather it in to merge with the existing ceiling paint.

Masking tape is better pulled off once the paint is still wet

its easier to get a straight line on the blue

in future paint the top of the wall the same colour as the ceiling so it blends better once the blue is on

If that’s bare plaster then leave it to dry thoroughly, then mist coat that bit yourself maybe, before just painting it. What lazy fuckers the builders were to pain straight onto plaster without a mist coat first.

I find using a sash brush is brilliant for cutting in to where the wall and ceiling meet, or other tricky areas. I rarely use tape, as the brush works well enough. This sort of thing…..

https://www.amazon.co.uk/Synthetic-Professional-Painting-Profiles-Mouldings/dp/B0C2Z9T91F/ref=sr_1_3_sspa?adgrpid=1185274432922652&hvadid=74079852972641&hvbmt=be&hvdev=c&hvlocphy=69201&hvnetw=o&hvqmt=e&hvtargid=kwd-74079787620337%3Aloc-188&hydadcr=27126_1850356&keywords=sash+paint+brush&qid=1702739576&sr=8-3-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

Don't let the paint dry with frog tape....remove whilst paint is still wet

Paint the bare plaster with a pva/water mix to seal then mist coat etc.

google the proportions, 1-5 I think.

I would do a thinned coat first (half and half paint and water) then another coat standard paint.

Do not use PVA! It will stop the paint adhering properly.

Do not use pva. For the love of god, I can't tell you how many people ruin their pain job doing this. Watered down emulsion as a mist coat is fine. Remove tape while paint is wet otherwise it'll take it with it.