Has anyone supported an AC to establish contact with their child?

I hope this is ok to post here as this is an estrangement of sorts and I’ve realised I really need some support for myself while we navigate this.

My son and his GF broke up recently. Initially she was keen to establish a contact schedule that was essentially 50:50 shared care for their (bottle fed) young baby but then cancelled a few times before deciding she would not be allowing contact until she’d sought professional advice following the one time she let the baby come to us. All communication was going through me and I’ve been at pains to be very gentle and kind in my messages (as I have always been with her) and just ask about contact on the days she’d suggested in the contact schedule. But now it seems she has stopped responding totally, not even to let us know how the baby is.

He’s been a very involved father from the beginning and very clearly and obviously knows how to take care of her. It’s been a joy to see him take so naturally to fatherhood, especially since his own father was almost entirely absent. But now I have to watch him go through the agony of being separated from his child whilst not knowing when he will see next them. My heart breaks knowing all he is likely to miss out on with the baby being so young. We have started on the legal process but it looks like it could be 6 months or more before he’s able to see the baby who probably won’t remember him by then.

I’m absolutely exhausted as this has totally taken over our lives; it’s all I think about and I’m not sleeping properly. I’m not really able to let myself feel the full force of what’s happening so I can stay strong for him. I suspect that his ex is acting out of hurt over their separation so I feel for her too even though this is causing so much pain for our family. I just wish she could see that we are not the enemy. He's holding it together but I worry how he’s going to cope once the months start passing and especially baby’s first Xmas.

Has anyone been through this and can offer any words of advice or encouragement please?