@purple99 Are you using pre-workout supplements? They can play a big part in being ‘foggy’ the next day depending on the intensity of what you are using.
There are some supplements that can help with adrenal fatigue if that is potentially an issue (it is for a lot of people) - Vitamin C, Magnesium, etc.
Diet and sleep are probably the biggest factors. I would try to eat as much whole food as possible, limit simple sugars except pre/post workout, and make sure that you are consuming ample protein - including some slow digesting protein before bed after heavy training days (Fairlife Milk, Steak, Cottage Cheese, Tuna, Protein Blend or Casein Supplement, etc.). When you look at sleep you need to consider not only the amount but also the quality. If you have sleep apnea, sleep on the couch, wake up to pee, etc. - then you may not be getting enough REM sleep.
Lastly, you could consider splitting up your squats and deadlifts into different sessions if you are doing both together and that one session is causing recovery issues.