I tend to not talk publicly about this because people tend to not understand and attack me in all sorts of way (as somewhat has happened to you in the Roland thread, and often much worse, also in person). I'll make an exception here since it looks like you need some guidance. If anybody disagree with what I write, feel free to ignore it, as I will if you respond to the message in the way that I am now used to š¤£
Since 2016 (or was it '17? don't remember for sure) I follow this almost vegan diet (some fish and extremely small quantities of some cheeses are allowed, some vegetables are not). It sounds somewhat similar to what you are trying to do...
It's not a "diet" per se, despite the title, it's more of a lifestyle. My health has improved in the last 5 years, I've lost 35 pounds (partially also because I run abouit 40km per week) and most importantly no new health conditions have started, unlike the vast majority of my similarly aged friends (I'm 50yo) and my younger brother. It's extremely strongly backed up by science. When I say "extremely strongly" I mean that for every single claim and suggestion there is compelling evidence by dozens of studies attacking the problem from at least 5 totally different points of view with very solid statistics, unlike the typical "newsworthy" thing which is usually based on one or two papers in which they saw 12% improvement on a sample of 73 individuals, but hey, nobody said that before so it's "news". These things are things whose evidence has built up for the last several decades, so they are "olds" rather than "news" and hence don't get the flashy attention they would deserve in a fact-based rather than sensationalist press. The 5 "points of view" are described well in the book, and very sloppily (but better than nothing until you get the book) at
https://lewishowes.com/podcast/the-5-pillars-to-increasing-your-lifespan-aging-in-reverse-with-dr-valter-longo/
Part of the lifestyle includes periodic fasting (which I do once or twice a year as a 7-day water-based fasting, since I find that approach perfect for me, however most people who follow this find easier to do a 5-day fast-mimicking diet and it's still very good). You can hear the guy talking about this part at https://www.youtube.com/watch?v=4LTe32ofHDI
The tl;dr; version is that a long enough fasting (at least 5 days), with possibly a small amount of selected food (the fast-mimicking part), puts your body in a "deep power saving" mode, in which everything that can be shut off is shut off because there's no much energy available. One exception to this is cancerous cells, which ignore pretty much any command to stop multiplying and attempting to grow -- the good news is, since they ignore the "power save" commands, and since there is not enough power available, they basically starve themselves to death, eliminating the chances to grow into a full-fledged cancer. They are now studying the possibility to apply this insight on sick people with very developed tumors.
As I wrote above, if you made it this long and have strong disagreeing feelings, just ignore it, as I will if you respond to it as I am now used to hear 𤣠-- I will respond to sincere questions about my experience with it if there are any