Bonemass gives the best challenge out of the 5 bosses, there's no shame in flattening the ground with a hoe or building a tree house, those tools are part of Valheim so adapting to overcome obstacles is simply part of a survival game, I'm sure many of us took multiple tries at bonemass however if you truly need a hand don't hesitate to ask, a lot of people here would gladly help you out. Best of luck to you Eilios