Eating back exercise calories, advice please

LastingChanges

Hi sorry for the long post but would appreciate any feedback. Everyone here advocates eating back exercise calories but my first problem is that I am still working on being more consistent with exercising. I plan and prepare my meals in advance for the week but since I am inconsistent with my exercising I dont require the same amount of calories each day. So on the days I am exercising I dont know how to add back those exercise calories to my meals. My second problem is I am not sure how many calories I should be eating? I have previously tried eating based on those TDEE charts and it was way too much food, it would make me feel tired, stuffed, and digestive issues.
I am currently eating 1500 calories, I have been doing this with and without exercising. I am 5'5, 153lbs. I need to lose at least 20 lbs because this weight is far off from what my body is used to and is causing all kinds of issues.
This is what my meals look like for now: breakfast 250, lunch 500, snack 150, dinner 500. I also drink a homemade bone broth, there is no way to estimate calories for it, I am assuming it adds up to 1500.
Since my meals are already prepared based on 1500 calories goal, how do I add the extra exercise calories.. Just as snacks is fine like fruits and nuts ?
On the days I do exercise I do boxing which burns up to 600 calories and treadmill which is 200. So somewhere between 600-800 calories a day. How many should I be eating back?

Also, does 1500 w/o exercising sound right ?

DeguelloTex

Start with half of what you think you're burning and see how that affects your weight.