I can't think of a single person I've ever talked to about writing that hasn't gone through the same thing. It's happened to me many times. My favorite method for breaking through the doldrums is to build a scene in my virtual railroading program or go flying. Both hobbies will keep your mind so busy you don't have time to overthink a particular roadlbock in your novel. Often enough your subconscious will provide a clue--the very key you need to turn your negatives into positives.
The writing I've done as little as a year ago is subject to my staring at it and wondering how the heck I managed to write such drivel. I gleefully rip out whole paragraphs, slash every adjective in the story, cream comma splices, and turn all tells into shows. Other times, I'll stare at it for ten minutes, then go have a cup of tea.
Trust me, you'll get through it.
Bill