Isn't isolating a parent abuse?

My ex contacted me for the first time today over money. He paid child support in late May for June 1st. I sent our dau to visit my son in OK and he decided to stop payment on check. Well the state had already deposited the money in my account so they are mandating that he pay them the money they deposited into my account. He texted me stating he wants me to pay that bill b/c I should not have taken the money out of my account.

He copied our dau on the text threatening to return her and baby to me. Then later apologized to her and stating he accidentally sent it to her although in the text msg he states "I have copied Sab in on this msg." My dau is concerned b/c when I went to drop things off last Weds he peeped out and then went got his gun before opening the door. I do not go inside when I do stop by. I have been there about 5 times but have stayed outside or on the 1st level. He lives on 3rd level.

Today she shared that he told her that if I come by there for any reason he is going to hurt me. I told her I would not be coming by. She and I just started talking on Friday but that was short-lived after today. She sees his anger and he shares in his anger. I think she is afraid of him, however glad she is getting the attention she has longed for regardless if its negative.Even if she wanted to see me or have me pick up the baby, her dad says no.

He said no to me on bringing the baby's crib to his place after Children and Family Svcs mandated our dau to have a crib by this Friday. I dropped some things by his brother's house for the baby and the crib, however he refused to let our daughter bring the items home because I brought them over without asking him. This is so sad. 

 I will not go to the apt for any reason. I don't want to be harmed by him. His anger is really rising to a new level to go and get a gun after seeing it was me bringing important mail for our dau. He's a controller and if he's not in control he goes crazy! I don't want the conflict to escalate. However, I do want to see my daughter and my grandson.  They don't have transportation.