I don't think you're being excessively needy but just thinking about what you mean to this person.

What I've found helpful is, instead of focusing on imagining what you think you mean to them, flip it around and ask yourself what they mean to you. If you value the friendship and want to stay connected then just keep the lines of communication open for now with an occasional text or call to let them know that you're thinking of them. Things change and people she's close to now may fall away and she will remember that you're still there for her.

It's difficult sometimes. I'm getting better at it now, at standing back in friendships when I feel like the other person wants space and finding that eventually things come back on track if its a valuable friendship from both sides. I've done the opposite many times and felt hurt and rejected and looking back, my negative beliefs about what I imagined the other person was thinking have damaged friendships and I wish I'd just stepped back and concentrated on the positive things I felt about them.