Aww bummer
it seems that your cycle either got screwed up somewhere or something happened, but looks like you are still on the thick of it
Refresh my memory: do you have a source of pure ammonia, or are you stuck doing fish food as a source?
Here's what I would suggest:
1) since you don't have high nitrites and you are doing a fishless cycle, I would add some more fish food or ammonia so that your ammonia goes to about 2-3ppm. Add some today, then measure again the day after tomorrow and see what your ammonia looks like.
2) keep testing for nitrites every few days until they go up. If they go way off the charts, it may be necessary to do a water change, but otherwise just let the tank do it's thing.
3) buy some plants. Not only are plants useful for your fish, they also often come with some bacteria on them (if you buy ones that are inside a fish tank) so they will help start the cycle as well. They will help stabilize the water parameters. Some plants can be sensitive to ammonia, but I see a lot of people with plants in the tank while they are doing a fishless cycle, so as long as you stick to hardy/run of the mill plants you should be fine.
4) try to get your hands on a bacterial starter, such as tetra safe start plus, Seachem stability, API Quick Start etc. Avoid stuff that describes itself as "contains bacteria to maintain aquarium" or "helps break down fish waste" and instead look for a product that says it will "jump start the nitrogen cycle" or "contains nitrifying bacteria for aquarium cycle".
5) try and follow this recipe as best you can to cycle your tank:
https://www.fishforums.net/threads/cycling-your-new-fresh-water-tank-read-this-first.421488/