Potence loss and shut down

So, I've took an E46 (320i, M54 and automatic) that my dad had and started driving, been driving it as a daily ever since January. When I first picked it up I did basic service (oil change, spark plugs) and left the cooling system for later (mainly to save up money to do the full repair). Hasn't got any problem until today, I was driving to work when uphill (the road has a prominent uphill) it started to lose power, also shifts didn't make it, at first I came to think it was a trans problem, but after passing the uphill shifts were made with no further problem, thing is after this event when I tried to get some rpm car shut down completely, no code jumped after this, not even the ECL light, it just shut down. I panicked and shut it down and then started it again, and I could just get to work and park it, thing is I tried to rev it up and it shut down again (parked) and didn't wanted to start off again. I'm at work rn but I can't get it out of my head, I might think it can be the crankcashaft position sensor, I just replaced the battery so I let it out of the discussion, and worst case isn't the transmission, but again, no code jumped, has anyone experienced this problem? I'd be glad if anyone could respond, thanks.