It's crazy because I sort of had this thing just happen to me with someone I really cared about as well. Also relating because I've never been blocked on anything either. I say that to let you know you are not alone in this.

In the long run, you'll see that it's better that way. Stop chasing after someone who doesn't care whether you're in their life or not. You got her a really (thoughtful) present and she didn't even have the decency to say thank you. Take it as a sign as a bullet dodged or the fact that she isn't ready for a love like yours yet. It's okay to feel hurt and to dwell on how things could've been, but eventually you need to move on. If you two ever cross paths again, great. But for the time being — give her space. It'll help you in your grief.