Your diet is horribly sugar heavy, it might have enough protein in it but probably not and that is it. As close to nutrition free as I have ever seen. You seem to know this because you are taking ensure. Your exercise is good enough, you are outside enough. But your diet, good lord it is very bad.
You need fruit, you need fresh vegetables, you do not need any refined sugar at all stop drinking so much . It should be a treat not the way you get your water everyday. Refined sugar will cause a big insulin reaction and cause low blood sugar. Vitamin supplements would be good for you. I have no idea why you are not constipated. Your diet is fiber free. You need to more than double your intake, stop drinking your calories. That leaves room for a huge quantity of fruit and vegetables by your standards. And have you considered mixing up your proteins a bit? Fish, chicken ,maybe game if you are into that. As far as fats you are getting enough but you could cook with Olive and maybe avocado oil and salads with olive oil dressings are good. And if you need more, beans of all types lentils.
Hint on vegetables as you do not eat them, you might not know what to do with them. Do not over cook and do not fear buttering them and salt to taste. zucchini sauteed in olive oil and light garlic is great
Another hint, find the healthy foods you like and eat them. You are going from nothing good to good food. Do not worry so much about verity.