Relatively new driver here.

There's a mini-roundabout I take nearly every day and ever since a close call I've lost my skill at navigating it smoothly.

From the perspective of my approach, this mini-roundabout has 3 exits - turn left, turn right or go back the way I came (no straight ahead).

What happened that one time was I was approaching behind another car to take the 2nd exit (turn right). I was checking around but especially to my right constantly and only creeping forward, but I didn't see the car approaching from my right until I was entering. They did not slow or seem in any way to react to me, and my reflexes caused me to brake and stop, which they ultimately did too, by which point they were heading directly towards the rear side of my car (I was at the bottom of the roundabout, before the first exit).

Of course this all happened in the blink of an eye, but my understanding of what happened is that they did not approach with caution. I think if I had come to a stop as soon as I'd seen them (a mere glimpse of their car through a tree), I would have ended up over the line much closer to them than when I did stop. Ideally, I wouldn't have braked at all and all would have been fine, but I saw them hooning directly towards me while I was going slow to make the turn and reflexes kicked in.

Now, I find myself coming to a stop every time I approach that tiny little circle to make sure no one's coming from the right, but this can confuse anyone to my left.

In the mornings, when I'm approaching from where that other car came from, I don't have a problem; this approach is down a narrow road of parked cars where the 40 zone turns to 30, so I always approach carefully, plus this approach has very good visibility.

Was that other car in the wrong that day? Did they approach and enter too fast/enter before they should have? Or should I have spotted them and not entered? (I really was crawling and scanning right, ahead and left on approach though). Or did I overreact and they just had a better sense of time and space than I did? I know without being there this probably can't be answered, but the real question is: how do I best enter this roundabout without the sort of hesitation that causes confusion or without too-sudden braking for the cars behind me?

I just want to avoid another close call or actual accident!