thank you for your reply. answering your questions:
1. I currently play on V12 reeds, strength 3. I own 2 mouthpieces, a Vandoren M15 and a Wodkowski one (sold to me by my teacher—I don't remember the model name).
2. I've tried playing long tones and scales up to 3 registers everyday, encountering the same problems I mentioned before.
I tried to post pics, but something must have malfunctioned. Let me try again...
the first and second pictures are my past embouchure, the third is my current.