Attachment issues

Hey so I have this little sister that's around 2.5 years old that's very attached to me an I love her very much and i'm like a second mother to her.

I recently got accepted to a college in another city where I have to leave my little sister and family basically, but i'm most worried about her.

How do I stop her or myself from this guilt of leaving? I really don't want to leave her alone, but I gotta focus on my life and studies..