Do whatever feels good and keeps your energy up and mind sharp. You may experience a significant positive shift with a new diet but when you feel like it's not helping, or even hurting, don't blindly stick to it - re-evaluate and change things up.

I personally don't have the microbiome for beans (not to mention the high phytate [antinutrient] concentration), but I do eat macadamia nuts because they have a good omega 6:3 ratio (ideally close to 1:1 for Americans because our diet is generally very high in omega 6 from vegetable oils).

It is certainly possible to do keto completely plant based but you'll be eating a lot of macadamias, avocados and coconut oil, and a lot of leafy greens with maybe some low-sugar citrus like lime and lemon mixed in for flavor. Don't think that's sustainable for very long but could be a good cleanse. Not a plant keto expert (or any expert, or a doctor, or nutritionist, or lawyer, or your lawyer....so do your research.)

I agree with QuantumAphid's suggestions for you, especially around intermittent fasting. IF is like your body's garbage collection process - stop eating long enough (ideally 16 hours) and your body starts to divert metabolic processes towards cleanup and restoration [1] in addition to burning fat for weight loss [2]. A combination of this and choosing a relatively low carb diet with high quality (organic) plant foods is great. For animal foods, go with pasture raised/grass fed - you want your food eating the food it naturally eats, not some processed, bastardized grain byproduct out of a freight car shipped from ADM or Cargill.

For now and the foreseeable future, minimize fish. If you really want fish, go with wild-caught Alaskan salmon or small fish like another poster said. Sardines are great. Stay at the bottom of the food chain... but monitor mercury levels over time. Seems like Pacific ocean mercury is on the rise from Chinese/Indian coal burning and Atlantic is finally on the decline from coal plants in the US closing down.

I will have to strongly caution against going long term carnivore or keto, however. Regardless of the quality of your meat products, animals still have metabolic processes that concentrate toxins, especially higher in the food chain. You need to set your body up for success by giving it a varied diet with nutrients from different kinds of food. This is anecdata on my part, but a combination of plants, which tend to detoxify and animals, which tend to nourish is my preferred long-term diet. It's not a popular stance out there because only extremes sell these days, but I am in favor of a balanced diet, a little of everything, mostly plants, and high-quality animal organ meats. Ruthlessly eliminate processed/fast and most packaged foods. My wife says this: is it food that your great grandmother would recognize as food? If not, don't eat it.

My wife and I have tried the extremes and have harmed ourselves, and had to recover from deficits. Each camp has their "just stick to it" reasons; there are many well-meaning people on the internet that are pro-vegan or pro-keto/paleo/carnivore and you have to assume that there is a need to continue getting clicks. There also may be a strong survivorship bias out there... however, the vegan survivorship bias is starting to show cracks (google "Rawvana" for details).

[1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3106288/

[2]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371748/