Weight loss after chin liposuction - will my face become hollow or start to sag? (photos)

Hi I am currently 22 and have an appointment for chin lipo and buccal fat removal coming up. I am 5'10 and about 200pds. I've lost 30 pounds but would still like to lose about 30 to 40 pounds. I know I should hold off til after losing the weight to get lipo but I'll be out of the country for awhile for school. My question is if I lose weight will my face become hallow or start to sag. Is losing 30 to 40 pounds to much and will removing my buccal fat cause me to look older as I age? What can I expect