Recently I gained stability and more control over my high C and am currently working on my high D but now the problem that I have is that when I slur up to notes like from third space C to top line F I sometimes go all the way up to a B flat above the staff. I use the straight line approach (Charlie Porter) and I can hear the F for a moment as I slur higher and the same back down.
I think that the reason this happens is because I've been used to weaker lips and facial muscles I've associated playing certain notes to a certain level of difficulty for my emboushure (so for example I would think of playing a G on top of the staff as being X level of difficulty for my emboushure) but since my emboushure has been getting a lot stronger, it takes a lot higher of a note to give me the same difficulty level. So instead of a top of the staff G being of X difficulty, a high C is that difficult.
My question is whether or not this is something I can fix using a certain method or way of practice, or whether this will fix itself as I become more accustomed to my new emboushure strength?