Question: Having Concerns About My Cycling

Hello! I seem to be having some issues with consistently cycling my tank recently. My Golden Albino Juvenile, Peach, lives in a 20-Long tank with a large sponge filter and fine, natural sand as substrate. About a month ago, the Nitrite and Nitrate levels were extremely high - 200ppm Nitrates and 5ppm Nitrites, which I had read about being deadly levels. I kept a close eye on it and talked with my Aquatics Expert at the Petco where I work. After a monthly full water change, the levels seemed to reset and have been extremely low ever since, which I imagine isn't incredibly healthy either. Peach has been acting normally and has a healthy appetite, which caused me to delay reaching out for information. Any suggestions for what I can do to stabilize the tank's cycle? I'll try to include some pictures of the Water Test strips I use and the results of a water test I did this morning. Thank you!

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I wasn't able to open the pictures, but if you're using strip tests they aren't entirely accurate so I would suggest getting the liquid test kids. API is probably the most popular on here.
Have you tried bottled bacteria to help it along? Or if a friend has an aquarium see if you can borrow some filter media and/or decorations to bring in some bacteria. This should help it along.
Do small water changes every week, nothing more than 20% unless ammonia/nitrite is high. The cycle will fix faster if you take the axolotl out as you can let levels get fairly high, so if you're able to rig up a temporary home for the axolotl (a tub with daily 100% water changes works) it may be easier in the long run.

Sorry about the pictures not working, they were pictures from my iPhone - not sure if that makes a difference at all, but I'm very new here. Thank you for suggesting the liquid test kits, I'm going to try looking into that the next time I'm out shopping. When I first started the tank, I had used Prime and Stability to get it going, which seemed to work well. I still have both of the bottles, if it would be a better idea to recycle the tank.
I have a five gallon tank set beside the 20 gallon tank he lives in now, so I could easily set that up and keep an eye on him while I fix the cycling in his tank. Thank you again for the reply!

You can also take samples to a fish/pet store if they do free testing until you get a liquid test kit. Prime and stability are what I use so I recommend them! If the 20 gallon hasn't cycled yet I would put the axie in your smaller one. Is the 5 gallon cycled or are you able to change the water daily?