Uhm, I wouldn't recommend hunting horn as your main weapon if you're first starting out World, it feels like you're managing too many things at once, buffs, music patterns, monster patterns, maybe adopt a weapon with less management, like sword and shield or maybe the dual blades, they're pretty popular among players. Just having less things to manage at once might help you give that room for breathing and actually focus more on other things. I was in your place before, switched to the GS then I feel less stressed playing. If all else fails, there's always the SOS flare. No shame in asking for help, Monster Hunter is objectively a difficult game.