Might also be interesting to try to figure out what’s actually shaking. You’ve indicated you believe your hands are the problem – but when playing the trumpet, the hands are going to move around if some other part is actually shaking (for example, your neck). Is it both hands, or just one? If you hold the trumpet in your left hand, can you get a steadier effect? Ditto right hand? What happens if you support your left elbow (for example, on a table) while playing trumpet. Does that help? At times it has seemed to me that even my breath “shakes”.