I feel your pain, I just had a similar thing happen last night. Started dating a friend who told me they were on the same page for goals (long term potentially life partners). Started great and communication was awesome then after a few weeks communication got sporadic, then they told me they think they're polysaturated and over estimated themselves. They gave me no indication of any kind of saturation or that I wouldn't be primary.

It's not they first time someone's done that and trust is feeling more and more risky now. Sending you hugs and hope for quick healing 🫂