ᐅ Touching Up Wall Paint – Smooth Plaster – Any Experiences?

Hello everyone

I will be moving out of my apartment in 3 months. I had a 6-piece picture hanging on the living room wall. I took it down and neatly filled the holes. Since the wall has a rather grayish tone and there were quite a few holes that I filled with white filler, I thought I’d do a good job and get the right paint to make it look better (the paint is about 4 years old). I obtained the color code from the landlord and had the paint mixed (emulsion paint). The wall is long and the light source comes from the front, so basically from a hallway. I also had some light pencil marks on the wall. I then proceeded with the following steps:
1. Erased the pencil marks with a white eraser and dabbed the round white spots of the holes with the paint.
--> Because of the front light source, the spots where I erased were shiny and clearly visible.
2. I thought, okay, I’ll just paint over where it’s shiny with a small roller (Image 1)
--> From the front, it looked good, the paint matched (Image 2). With the light source, it also looked fine; against the light source, it looked bad (Image 3).
----> Problem: The paint was not rolled out smoothly to get a clean color transition AND there were “peaks” at the edges creating shadows.
3. Thinned the paint to reduce the peaks; the paint allows up to 10% thinning, I used 5%. I also rolled carefully until there was no paint left on the roller.
--> It kept getting worse :-( (Image 4).

What should I do? The wall is huge, I don’t want to repaint the whole thing, and I seriously doubt I can fix this given how tricky it is.
Currently, I only see the following options that might help:
- Different roller
- Thin the paint even more

I would be really, really grateful for any advice.

Best regards

Black Rider