It must be really terrible to suffer like this. Glad you had the courage to write about it.
First, I would check with your doctor. There are certain genetic disorders characterized by what's called morbid hunger - ie. Kleine-Levin Syndrome, Prader-Willi Syndrome - not saying you have these (would have to know more about you, but you can google the symptoms), but at least you should have your thyroid levels, etc. checked. Always first rule out any medical causes.
Then, what do you actually weigh? If you eat enough for your weight, activity level and metabolism, you shouldn't be hungry all the time, unless there's a medical or psychological cause. 1500 calories a day might not be enough to sustain you - there are lots of on-line calorie requirement calculators (ie.
Calorie Needs for Men). If you require 2500 calories a day to not feel hungry, going to 1500 cold turkey will be very hard. Figure out your maintenance calorie needs, then gradually reduce so you won't feel so hungry.
If you've already tried that, I'd suggest increasing your activity levels and seeing if you can find low calorie foods that will fill you, like raw vegetables.
Finally, if none of that is the answer, consider whether it's Emotional Eating. A very complex phenomenon psychologically, but there are supports groups for this, like Overeaters Anonymous. Often arises out of a history of trauma or neglect, can be a result of needing to fill some emptiness or trying to self-reward for over-working and neglecting your needs. Something to raise with your psychologist.
Hope some of that is helpful. Congratulations on reaching out for help.