Shaman dragón, what’s should I focus on? Please help

Hey everyone, I'm a Dragon Shaman, currently level 111, with good gear and a Bright Diamond for now. I was wondering how I could get the most out of my Dragon Shaman at my level (111 and rising) by fighting bosses? But which boss would be a good match for the Shaman? I was thinking of starting with the Sovereign, since the Hydra seems super difficult at the moment. Maybe Balathor in the future? What do you guys recommend I do as a Shaman? What should I prioritize to get the most damage with my Shaman, since it's my main build? Another thing, I see in videos of Shamans (like Cheffius, for example) doing 110k damage with one skill. If I don't have that kind of damage, can I not aspire to anything? Because honestly, I'm way behind. I'm using full Demon gear, and in the Forest, I only do 25k damage with Roar... Please help me, I want to improve my Shaman and become one of the good ones. I don't want to give up and end up creating a wasu like everyone else (I know they're the best at everything)... thank you very much in advance