Separate Parents and Anxious Toddler

Hello, My grandson is two years old. for the first year and a half, my son, his girlfriend and son has lived with me and the baby slept with them. About six months ago they broke up. She moved home with her parents although they shared the baby 50/50 and he was fine. A couple of months ago, my son moved out, at first the baby was fine, even slept in his own room with my son's roommates three year old son.within a couple of weeks, he would no longer sleep in his own room, only with is dad or 10 year old brother. Within a couple more weeks, he has gotten to where he doesn't even want to be in that house at all. He cries and cries and says, "see mama, see granny, sleep mama, sleep granny" it's not just a normal cry, it's a panic attack with heart palpitations and so on. My son can't get up to cook, clean go to the bathroom etc, he wants his daddy or brother by his side every second. I babysit while my son is at work, he's fine, he say's the normal stuff "I see Daddy?" When my son comes to pick him up, he's fine as long as My son is holding him or playing with him etc, but as soon as it's time to go, he goes into his panic attack and wants him and his daddy to stay here, it's so sad, because, he say's "daddy stay" it's gotten so bad, that he leaves him with me, and the baby hugs and kisses his daddy and says " bye daddy I love you" he wants to go but can't seem to get past the panic attack, I think he's use to this being his home. When he's with his mom, he has the same panic attack when she goes to work or anytime she leaves the house. Or when she picks him up from his dads or our house, he cries and says "I see daddy?" When he picks him up from her, he does the same, "I see mama?" Please advise how to cope and help him get over this. Thank You, Rhonda Valdez