I'd like to interject.
Sound is THE most important thing we have. How do I know this? Because the first compliment one is given is "That SOUNDS good" or "So-and-so sounds good!". Not... "Wow... that was a high note!" If the job is done correctly, the listener should NOT be thinking about how high whatever note you just played was. Just how good it sounds. I saw Wayne Bergeron a couple of summers back. It did not sound like or look like he was playing high at all. Just the most open, focused and beautiful sound imaginable. And in tune.
Also: dynamics are relative. A forte dynamic for you in that band is completely different than a forte in a pep band. Your forte must blend with the forte of the flutes. Or even that lone clarinet player. I remember a conductor telling me once: "Forte means full". So, fortissimo is very full. Not loud. Loud implies harsh, forced tone quality.
Have you taken a leadership role in your band? Are you someone the trombone players aspire to? If so, try encouraging them to breathe fuller. Examine their posture. Maybe they are slouching and not breathing fully. Consider what a leader really is; who the leaders you aspire to or wish to emulate, and ask yourself why you want to emulate them. Instead of looking at them and seeing "suck", remember they are people. They are in band; that's half the battle. That means they want to be there. That means they want to play. The rest is in delivery.
BTW... the analogy of stage make-up is one I love. I encourage my students to over-play style. That's how they find the boundary of what is acceptable and tasteful.