damaged wall - does is all need repainting

If the paint on that wall is old, will always be able to see the difference between coats.In my opinion for a better job do the whole wall.

Make good with external fillers.

Lol these things happens a drill hole is normally small and round so you could use filler and a little sand paper to smooth the the wall before painting. Sounds like you punchered the wall with the pressure you used on the drill and made a big hole. No problem break that little plaster you made out make a new one this time only put a little and use a damp sponge not wet and level a little if it's not level don't worry make sure you got at least 1 2 cm hole let it set a little for 15 min as it looks like it's going to set get a brush dump it in water then brush the hole then let it dry. One dry add filler easy to smooth get your self rough to take away excess filler then get a fine sand paper to give you a smooth and level finish.

All you need is just repair that wall and repaint. You dont need repaint all walls.

It would be better to repaint the whole wall then you can repsir the damage in one as well. You can just repaint,but run the risk of the two oaints not matching up due to age or even a different shade

depends what paint was used and how long its been painted. ie you cant touch up eggshell as it flashes. all colours fade over time so it may be polite to do the whole wall.

You can paint only part if it is the same color as you will not see a difference there is no need to paint the entire wall. Regards PNZ

If you have the some of the original paint you can just touch up the damaged area. However, the plastering must be complete first. To fill a small hole, push in lightly the hole edges using the handle of a tool such as a screwdriver or a scraper so that they don't stick out. Scrunch up some tissue or paper and place in the hole making sure none sticks above the surface and leaving a couple of millimetres for the plaster - this stops the plaster from pushing through into the void. For just a small hole buy the smallest amount of ready made up filler you can buy to save waste/costs. Ready made takes the guessing out of getting the mix right and saves time. Fill the hole and smooth off with a scraper making sure it is flush with the wall - some small gaps are OK at this stage just try not to have any sticking up. When dry, apply a second coat leaving it just a millimetre above the surface. Allow to dry and lightly sand until smooth then it can be painted. For larger holes, use the method given in https://www.youtube.com/watch?v=AC0MnCTPGoU and where they say compound it means filler and jointing compound can be replaced with a glue such as Nonails. If you have plastered and it looks wrong, carefully scrape it out and follow one of the methods here. Still stuck then message me.

Well I would think it best to give the damaged area a good sand down to a smooth finish. Then if you have some of the old paint to use it can be patched painted to blend. only most would just re paint the whole wall.

To look good it has to be repainted whole wall.

If the paint is a shiny one thats already on wall such as vinyl silk it may show up that uve touched it up if its matt paint its generally fine to touch up