Hi there,
Your post has triggered a number of thoughts I have on the subject.
1) You’ve done a lot of comparison to others which is futile. You will always find people that are stronger naturally and seem to play with ease. I would ask myself, Am I doing enough physical conditioning ( running, walking, swimming, etc. ) to be able to play at my optimum?
2) Are you obsessing about the lips? I would recommend Claude Gordon’s book ” Brass Playing is No Harder Than Deep Breathing”. I’ve read Gordon used to say “Forget the Lips” to students quite often. And don’t forget Greg’s quote “The lips respond to Airflow.”
3) We’ve all experienced the horrible feeling of an overtaxed embouchure. There’s nothing you can do at that point except put the horn away and get a good night’s rest. I’ve been doing Greg’s routine for quite awhile and I’ve experienced improvement’s in range, endurance, and consistency. I attribute a lot to emphasis on relaxation (releasing all unneeded tension) and aperture efficiency (concentrate on aperture corners not embouchure corners). Those Singing C exercises are incredible if you do them properly and consistently.

Good luck,
Brian