not having enough calories but too much sugar...

Stop drinking juice. If you must, water your juice down, or blend it with a handful of ice. I pretty much stay away from juice and limit my fruit intake to 1/4 cup frozen mixed berries occasionally and the morning 1/2 banana added to my protein shake. Increase your protein and sugar won't even be on your mind. Also, unless your doctor has you on a VLCD, 1000 calories is going to eff up your metabolism. I eat small things, usually in 200-250 calorie increments 5-6 times a day, or about every 3 hours. It's tough and sometimes I feel like I'm forcing myself to eat BUT it prevents my sugar from getting low and thus I am able to make smarter food choices because I'm not craving carbs. Snack size baggies, tiny food containers, and 15-20 minutes before bed prepping for the next day will do wonders.

If your goal is less sugar, then you simply must cut way back on the juice. Sugars are carbs, it doesn't matter if it's from cake or fruit. Then add more protein, dairy and healthy fats to increase your calories.

An idea, drink less juice and add water and protein powder to it.

For your soups, you can add beans and peas, they contain more proteins and less sugar than fruits. Fruits and veggies (I mean fresh veggies, not legumes like the beans I suggested) are essentially carbs and micronutrients, which is good but very poor in proteins and fat and you risk some serious health problems if you don't eat enough proteins. (You also risk health problems without enough fat but you'll feel the lack of proteins way sooner, if not already.)
Fruits and veggies = good, healthy. Only fruits and veggies = not good. If you tolerate liquids better than solids, protein powder seems a must add until you resolve your phobias. Adding cream and milk is also an idea to add proteins and fat and up your calorie intakes to 1200 min.

I don't know where you live, how your insurance works or even if you have one, but it seems like psychological help is crucial to maintain your health, at that point. I don't know if there's any way you could afford that help, for free or with the help of an insurance. (In my country and most of the countries around mine, there are free "psychological centers" and insurances cover psychiatrists though not always psychologists and other non medical psycho-something. I don't know how it works where you live, but you should definitely do some research on what is offered and/or insist to have more help from your doctor.)

I do think a diet in your condition is dangerous without medical supervision. How did you manage your food phobia before ? Did you always lack fats and proteins (because if you're under 1000 kcal and have too much sugar there's no way you have nearly enough proteins and fats), or did your diet change recently ?

I used to juice a lot when I first got my juicer. Then as I researched it more everything I read said do NOT juice fruits as you strip away the fiber that keeps your body from absorbing the sugars too fast. It said to only juice veggies. What I did to make the veggie juice taste better was to add a small bit of fresh ginger root (you can buy it at any grocery store) and half a lemon. Also you can throw in half an apple to make veggie juices more palatable. Now I eat my fruit whole and unfortunately I can't afford to juice at all right now so I am also eating my veggies whole. I liked juicing the veggies because i would get a greater variety that way since there is no texture to deal with. Also I added benefiber powder to the juices. I'm also trying to cut my sugar intake for non-medical reasons (preventative) and it IS very hard. Take it one day at a time and remember that tomorrow is a new day to try again

Increase your Protein, this will benefit you so much --- go for lean protein sources.

Try to get more protein and fat, it will bump up calories and reduce your sugar intake.