(S)He's just not that into you.

If someone doesn't seem to be emotionally available to you, it does not automatically mean

1) that they are emotionally unavailable generally, or
2) emotionally unavailable to you forever.

A person who has an intimate relationship with the depth, richness, and sacredness of their heart and inner world is likely to be discerning about whom they share that with, and at what point in the evolution of a connection they are ready to open to someone.

And it may be that

1) you're just not it for them, or
2) they have a healthy relationship with themselves and as such are not likely to love bomb you immediately.

It's not personal. A person showing up this way isn't ALWAYS dysfunctional and avoidant. It could be that what you're experiencing is their greatest gesture of love and kindness: saying "no" or "not yet."

I know it's confusing. Which is why you really don't have to take it personally either way.

Also, while I have you here:

Someone who is open-hearted and receptive is not automatically interested in a sexual relationship with you.

It is in fact possible to have non-romantic relationships that are made up of deep, intimate, nourishing bonds with all genders (something we have unfortunately reserved exclusively for romance and partnership, or have conflated with sexual arousal in the past).

Let yourself re-write your story about how you want to relate with others. Give yourself a broader palette of connection to be fed from. You do not have to be emotionally/sexually available to everyone just because you have an open heart.

You can open your heart unconditionally and totally.
And.
Having an open heart includes discernment.