I thought I was taking a break, but now I'm just not sure I want to do it anymore.
I am new to fiction as well. I was a non-fiction writer/editor for years. Maybe in about a year or two I'll post the same question you have posted. I don't have an "answer" but I wanted to comment on the issues of critique and motivation.
It took me years to become proficient at writing/editing non-fiction in my narrow field. After the first year, I looked back at what I had written and was suddenly ashamed of the errors and weaknesses I saw. That continued to happen, although it diminished in intensity, year after year as my level of skill improved. As your abilities grow, so does your inner critic. It's possible your critic is leaping ahead in terms of development while your writing skill is developing at a necessary pace. It often seems that writing is a more time-consuming, complex skill to learn when compared with critique.
When working in nonfiction, there were days when I felt like I was "on" and I had great confidence that I could write anything needed quickly and efficiently. Then there were days when I wasn't "on" and words were like bricks that I couldn't fit together no mater how hard or how long I tried. I hated everything I managed to cobble together.
The difference between "on" and "off" usually had to do with factors like burnout, motivation, and long-term stress. For me, the best method of overcoming the "off" state is to reboot my stress and frustration levels by becoming active in other distractions (e.g., physical activities, music, recreation).
The most effective motivation for writing I have found is the method for priming creativity described in the book, The Artist's Way. If I write 3 pages the moment I wake up (it doesn't have to be work, any writing 'counts') every morning, then around week three I find I HAVE to write. Words come pouring off my pen at all hours of the night and day. The other part of the program described in the book includes a 2 hour "play date" every week. You set aside time each week to indulge creative whim.
As you can see, I don't have the answer. I just wonder if you are pushing yourself too hard and enjoying it less. I see alot of good advice in the other posts on this thread. In particular, I wonder if you have already explored other writing niches like essay, short story, poetry etc.
Noting your clear-eyed willingness to judge the quality of your work and assess your interest in continuing, I am greatly encouraged for your success in whatever you decided.