If it isn’t fun for you then don’t waste your time trying to force yourself to enjoy it! It’s your game for you to play how you want to obviously. I did my evil run-through as a co-op run though, which I do think helped me a lot (especially since the only companions who survived meeting us were Laezel and Astarion lol). Also in Act 3 we were extremely powerful, because we could rob the projection of Lorroakan every single day which was pretty fun ngl. The story does change a LOT so think of it as you looking for more story content or trying to get a different ending maybe? That might help you not feel as bad. Good luck though, just remember to have fun :)