I agree that you mustn't let a tup dominate you but if you are small or not particularly strong, you still have to handle them. Try driving him into a pen of preferably 4 ft hurdles then decrease the size down to just three in a tight triangle; he can't go anywhere much or take a run at you. Whilst leaning in from outside the hurdles, reverse him into a corner, lift his chin with one hand and squirt the wormer liquid into the side of his mouth with the other. Handling a tup by the horns makes him resist, lifting his chin relaxes him. Trying to catch a strong tup by the horns out in the open field if your hands are not strong enough to hold him firmly is asking for an injury. How have you been doing his feet?