You have already taken the first, and most important step towards health...acknowledging that you alone are responsible for it, good or bad. Restrictive diets, no matter how they are structured, usually result in weight loss, and so, in improvements in short term health. The rub is ALWAYS your ability to stay on them long term, and with some of then, the long term affect they will have on your health.

There is extensive and robust science showing causal links between saturated fat consumption, animal derived protein, and cardiovascular disease/stroke and cancer. Further, a diet deficient in fiber can lead to a host of digestive track issues as well as deficiencies in important short chain fatty acids.

Eliminating the heath damaging elements of the Standard American Diet (highly refined and manufactured "foods", trans fats, saturated fats, high sodium) will nearly always result in health improvements. Adding whole foods, including most plant foods, will nearly always result in health improvements. One great advantage of whole plant foods is their reasonable cost. I routinely make a pot of veggie/bean chili, get 4 meals out of it, and spend maybe 4 dollars;)