I have tried every approach at diet and working out. I have tried 5 small meals, intermittent fasting, keto, high protein, diet breaks, carb reseed, working out every other day, doing workout splits, high volume, powerlifting, etc. I can’t seem to lose any fat/weight, and haven’t gained any muscle or strength.
There are 2 key elements to getting a good physique, diet and workouts (as we all already thought). Both of which need to be done right.
Personally I consider any fancy diet (some of which you mentioned in your question) pretty much useless if you don't monitor how much you're intaking. The key to a good diet is to take in around 500kcal less than you burn, thus making you lose fat. What excactly you eat, when or how often doesn't really matter. Although it should be mentioned to try and eat healthy obviously.
For your workout, you need to get a good workour routine and a progress plan. What weights can you handle now determines what you want to reach in, let's say, a month. That numbers should already be clear to you roughly. You therefor need to progressivly overload your exercises. If you can lift one plate more than last week, great! Go ahead and lift that. If not, atleast try to do one more rep. Then two more, and so on.