I am struggling with Totem Marowak My team is a Level 23 rockruff, a level..

Judging by your team, I'd say the problem is obvious. Alolan Marowak is a Fire and Ghost type. This puts Eevee, Hawlucha and Dartrix at an immediate disadvantage. Additionally, the Totem Aura increases all of Marowak's stats, making it a powerhouse. I would recommend leveling up on the slopes of Wela Volcano and use the most powerful moves at your disposal that are Supereffective against Fire and Ghost. The Salazzle (or was it Salandit?) it calls in can be a nuisance with it's Venoshock move, but I would focus first on Marowak. A word of caution, though. Good odds the Salazzle/Salandit has the Corrosion ability, so Tentacool's Poison typing won't protect it from the Poison status condition. I would also suggest leveling everyone to match Dartrix and evolve Rockruff, Tentacool and Eevee (which can evolve into Sylveon quite easily by having 2 hearts worth of affection in Pokemon Refresh and knowing a Fairy type move - such as Babydoll Eyes)

If you have the knock of TM knock totem marowaks item of the use a watering z with your tentecool after level up a few levels and it should’ve be easy peasy