How can I show her I just care and not trying to har her?

It sounds like you still care about her a lot, but get a hold of yourself and don't contact her for 2 weeks. You are sending the wrong message by wishing her well on her exams if you are no longer together. Would you send a text to a buddy who just finished exams? It is hard to redefine a relationship after you break up but you can't expect things to be the same. You both may still care about each other but if you don't take time apart to adjust, you'll just get back into the same old rut. Check up on her in 2 weeks, until then leave her alone unless she contacts you.