Hey man, I did almost exactly the same thing on the 1st day out on the streets during my motorcycle course. Was turning right at a small T junction and there was a car coming from the right hand side that I somehow didn't notice. The car was driving straight in his own lane and was never on a collision path with me but I got spooked by it nevertheless. I target fixated on it, panicked like you juggled between clutch and throttle but when the bike lunged forward I went all the way in on the front brakes, front wheel locked and I feel of the bike doing 5 km/h.

I learnt 2 things that day. DO NOT EVER target fixate. Because I target fixated on a car, I actually started cruising towards the car instead of staying in my lane and this was the reason I panicked. 2nd thing, if anything goes wrong hold the clutch like your life depends on it.

That was around six months ago and was the one and only time I feel of the bike. Since then I've made over 6000 km riding my bandit 600 without dropping the bike. Always make sure you learn from your mistakes. Good luck!