Family separation issues...?

okay..in exactly 2 weeks from today, my brother is going away to college..and im going to feels really lonely..and it makes me sad how we have a baby sister only 2 years old...man..it makes me sad that my older brother has to say goodbye to us, after driving him to his college..will she remember him? im not sure...but people try to understand my situation..i know its easy to read this and say.."oh it's not a big deal" but for me it is..it makes me real sad.. every time i think about it..it kills me in my heart...and we usually do this farewell senior party at my church...im expected to go up to the mic and say our last words to them before they go to college...man..its going to be hard...but what makes me feel a bit better is that..we can video chat..but i don't know...ive been with my brother for 15 years...we lived in the same room, we grew up together, had our laughs and everything...now its goodbye...UGH...and my baby sister...she won't have a CLUE of what's going on...man...how hard will it be on my brother to say goodbye...i can see in my brothers eyes...he is upset of leaving....man its going to kill me....i dont think ill get over it in a while...but im 15 years old, so i think i can handle it in 2 or 3 weeks..i hope so...maybe not...idk...i need help....any advice? how long do you guys think i will get over it? what should i do?