[STUDENT] Stall to spin question

I'm a solo student, 29 hours in. This morning I checked out one of our club 152's to go do my practice maneuvers and work the pattern. Nice, super early morning, 7AM, no winds, 74 degrees, density altitude 1700 feet, dew point spread good.

Climbed up to 6,500 feet over the practice area. I normally practice with my CFI's at 3,500 feet, but altitude = insurance and it was a gorgeous morning, and I was getting close to 1000fpm climb in a 152, something I'd not seen before so I worked it.

I do my steep turns, no problem. Textbook, if I do say so. No loss of altitude, exit on heading, hit my own wake.

Power-on stalls no problem. Only did one, but it was fine. Decent break, rudder to the sky, recover with minimal loss of altitude and positive rate of climb.

Then start my approach (power off) stalls. My first one broke normally, really lightly, and recovery was a snap, total loss of altitude during recovery was probably less than 50-ish feet once the stall broke.

However... my second one, with the same setup, and the outcome was totally different. I pulled back to 40 knots then 35, and instead of a gentle break on a power off stall, I got a fairly violent break to the left, my left wing dropped, and before I knew it I was face down, and falling. I recovered quickly - power to idle (it already was, this was a power-off stall), ailerons to neutral, rudder opposite spin, elevator down to gain airspeed, return to level flight, and then apply power back to a positive rate of climb.

I estimate I went 270 degrees before I recovered, and lost about 500 feet of altitude.

I recovered, trimmed for straight and level, and then let my bung unpucker and my heart rate to come down to some semblance of normal. Also, I just sat there for a moment wondering what had happened.

If that had happened on approach, I'd be dead. (I hold 60 knots on approach to avoid exactly this.)

I have probably done 30 or so power-off stalls, and I'm 80 landings in. I've NEVER seen that happen.

I'm trying to replay what I might have done, and the only thing that comes to mind is that when the stall broke, I was at a much higher angle of attack than normal, and I kicked the rudder in the wrong direction when the stall broke. My CFI has been coaching me to pull back further on my landings, and that's what I was practicing at altitude.

Any ideas what I did that caused this? I'd like to never do that again. That said, it was a real learning experience. First off, had I not recovered, I would have ended up in a full spin, I'm sure, and secondly, I got to put into actual use the PARE technique to recover, and did it instinctively. I didn't die, and the plane was reusable.

But it scared the crap out of me.

Thoughts? I know this is a rudimentary question, but I'm really wondering WTF happened. I'll also review with my CFI tomorrow when we fly, but I'm hoping to understand it better before then.