Well, it seems you may have fallen prey to the "too much bike too fast" situation that many of us here tirelessly try to steer new riders away from.
If I had that many crashes in a short period of time I'd be soul searching as well.
So, a few questions:
1/ Did you actually ever get any formal training when you started riding? How did you get your M2/M - a course, or just the minimal MTO route?
2/ Are you willing to go get more advanced rider training? Things like dumping on streetcar tracks IMHO is rooted in lack of situational awareness as well as over control - more training can help. Certainly can't hurt.
3/ Are you willing to admit you have too much bike and either downsize or switch styles completely, IE SS to Adventure, or heck, cruiser? Or are you stuck hard and fast on the sport segment?
If the answer to both 2 and 3 above are not "Yes, absolutely", then I think it may be time to hang it up.