Congratulations on quitting smoking and caffiene, thats no small undertaking! You will likely see improved effects over the next couple of years as your cells continue to renew and your body chemistry changes.
Have you ever considered having your mineral levels tested? Do you take any supplements? It might be something as simple as having low potassium and magnesium, as these are striped through stimulant use as well as it sounds like you may have been eating a diet higher in sodium. Both potassium and magnesium are very calming and healing to the heart and can help with palpitations. Adding high quality salts, from seaweeds and seafoods especially, and also supplementing until you are more healed might be a good idea.
You may also do well with adding more high quality animal fats, instead of egg whites and a green smoothy, eat the whole egg lightly cooked, the yolk has more nutrients that more bioavailable and easier to digest. The fats are excellent for your heart and egg yolk has the benefit of choline which is excellent for digestion, amount other things. You may also be overdoing the protein and not getting enough fats, which can cause compromised digestion and inflammation. Try to eat more fatty seafoods, grassfed meats with gristle and fat, raw dairy, offal...get the full range of animo and fatty acids, even if you are cooking them it will be extremely beneficial.
If you are going to transition back to cooked foods, I would suggest learning how to very lightly warm foods, and figuring out how you can create meals you can take with you, as they will be far more beneficial to your health and wellbeing than most any prepared foods you can purchase.
