Mercenary feels very weak

im deep into act 2 at level 33 and i barely deal any damage whatsoever, i keep farming older areas in the hopes to drop anything but find pretty much nothing i can use, im still stuck on a level 10 crossbow after gambling 40+ new ones without getting anything usable.

there are barely any damage nodes near the merc tree that do anything for me and i honestly have no idea how im supposed to progress as the current boss (jamanra) takes so little damage its not worth any further attempts.

i dont mind the game being difficult but this feels like i am not giving the right tools to do anything

any other mercs with the same struggle or maybe some tips?