I know exactly how you feel. Currently, I'm living in Los Angeles while my girlfriend (1L) is in Chicago. She's absolutely miserable most days, and I get the EXACT same types of communication that you do too! The minimal text messages, and brief phone calls all sound exactly like what we're going through.
One thing that has helped us (me) a bit is just setting a time when you both can speak during the day. Though many days we have to scrap this plan, it really helps me to not look for her messages or phone calls all day. After all, it's terrifying, right? There's so much change happening that you don't know what's going to happen.
One other thing that seemed to help her a lot was getting in touch with a bunch of her friends, sending them cards, and having them fill them out and send them to her. She really appreciated the fact that so many people in her life really believe in her ability to succeed, and it helps her to feel a bit more secure in a constantly changing environment.
I hope all works out well with you two, especially since I am in a very similar and familiar boat!