If you selected “lose weight quickly” the calculator deducts 25% of calories from the amount needed to maintain your weight. To exercise every day and maintain your weight you need 2985 calories per day. Since you are only getting 2000 from Soylent you are shorting yourself 985ish calories.
To lose 10lb a month you should have to be shorting yourself 35000 calories a month. 35000 / 30 days = 1167 calories a day deficit.
Losing 10lbs a month could be why you are so fatigued all the time. You are just running out of gas so to speak.
I’m curious what’s the hurry to lose weight?
That would work. Should always have a good amount of protein after a workout, your muscles with thank you. Might be more convenient to add it directly to your pitcher of Soylent and drink that after your workout.