is it normal to be so astronomically depressed leaving for uni

i’ve always been bad with change but ever since my brother moved out i’ve been a constant short fuse idk how to explain it like that was really hard because it was just so different and i thought we’d be kids forever so it felt so sudden despite not being so, then after MONTHS i settled with the new norm but the next year my sister moved out and it was really hard again and i’m still grappling with my emotions even now i know this sounds dramatic but it’s hard, now it’s me this september and my two little sisters soon after and i’m hit the worst i’ve ever been i feel like i’ve been the worst sister ever and i’m afraid of just leaving obviously i’ll be back for holidays but it’s not the same and since like i’ve processed this is real and i will be leaving i’ve been just crying every night this isn’t an exaggeration is this normal sometimes i just can’t snap myself out of it i KNOW in my head i’m being dramatic but i can’t stop myself from processing in this way and i’m just afraid of everything and i’m scared of the change AGAIN and i hate that i can’t go back to how things were and i don’t know what’s wrong with me i’ve been crying every night since like january.

Yes! It is definitely most normal.
I share a similar situation, but instead of Uni, I go to a boarding school - separated by a 14-hour flight from home. It's been 3 years since I've left and also have dreaded in the past as I'm scared of how everything will change; in which things won't be the same as before.
Nowdays, I realise sometimes change can be good - and that we all will experience in life. Whether the change comes early or late, the change will still arrive somehow!
I want you to know you're not alone and change is a normal element in our lives. Furthermore, I know you are a strong, independent individual who can and will face the challenges ahead.
You can do it - I know you can!!
I wish you all the best, good luck!

i’ve always been bad with change but ever since my brother moved out i’ve been a constant short fuse idk how to explain it like that was really hard because it was just so different and i thought we’d be kids forever so it felt so sudden despite not being so, then after MONTHS i settled with the new norm but the next year my sister moved out and it was really hard again and i’m still grappling with my emotions even now i know this sounds dramatic but it’s hard, now it’s me this september and my two little sisters soon after and i’m hit the worst i’ve ever been i feel like i’ve been the worst sister ever and i’m afraid of just leaving obviously i’ll be back for holidays but it’s not the same and since like i’ve processed this is real and i will be leaving i’ve been just crying every night this isn’t an exaggeration is this normal sometimes i just can’t snap myself out of it i KNOW in my head i’m being dramatic but i can’t stop myself from processing in this way and i’m just afraid of everything and i’m scared of the change AGAIN and i hate that i can’t go back to how things were and i don’t know what’s wrong with me i’ve been crying every night since like january.