How do I fix this mess?

[BettyBoo]

I'm not much of a handywoman. I replaced the fan in my shower recently and as the old cover was painted over it took some of the nearby paint and plaster off. Now the new one is up but it looks a bit of a mess. What gap filler should I use before painting over the surrounding area? As its an old shower it gets a bit damp and steamy up there as you can see from the photo taken just after I had a shower. Thanks for any help and suggestions.

[aussiblue]

Polyfilla Small Cracks filler https://www.bunnings.com.au/polyfilla-770ml-interior-small-cracks-filler_p1210371 or better this one for bathrooms and kitchens https://www.bunnings.com.au/polyfilla-770ml-bathroom-and-kitchen-filler_p1210573

[BettyBoo]

Thank you. I assume that is OK and easy to paint over? The website doesn't seem to mention that. 

[Kermit]

No problem with painting it. Just make sure to get it as smooth as possible, then sanding after it has dried.