Struggling to Get My Daughter Back from Grandpa

...possible trigger warning... I'm a bit nervous; long story short my eldest daughter (now 4) is living with grandpa under CPS orders because I needed to work on my mental well being and focus on myself for a bit. well now that I have, I have a second daughter now only a couple months old and have been cleared by CPS. well grandpa is refusing to give my eldest daughter back to us because of his own selfish feelings and pride (he's never liked me n hates his son) it's been about a year and a half and in that time, grandpa has not allowed us to talk or see our daughter, n when we try he purposely tries to interrogate us to start a fight, then gaslights and hangs up. we have been instructed to not talk to him because it has caused enough emotional stress to physically effect us (anxiety attacks, crying, spells, severe depression, even fainting) just saying her name triggers a crying spell because I miss her so much... my partner on the other hand has gotten angrier and more hostile towards his father; not only just because of the situation with our daughter, but because of all the abuse he went through as a kid because of him. he needs to renew his driver's license and I fear that he will actually go through with doing something drastic when he does.