visitation

I have full sole and physical custody of our two children and my court order states father may have visitation as both parties agree but he's not aloud to speak to me at all due to his jealous girlfriend. He has his mom call me whenever he decides he wants the kids for a weekend. When I go to drop off the kids there's always a fued between me and his girlfriend. This past weekend I met them to drop off the kids and my son forgot his hunting license so his dad started yelling at him and his girlfriend started calling me names in front of my children. I got out of my vehicle went to theirs and took the children out of his truck and told them to get in my car and my ex me and his girlfriend got in a huge argument and I brang the kids back home. It's always a problem with her present. My kids also said they get high and drunk when they have them for the weekend. I can't afford a lawyer and legal aide won't help though I think it needs to be taking back to court.