Baby daddy drama

I was with the father of my oldest child for three years. In the beginning it was amazing I was so happy so when I found out I was pregnant it was a huge surprise however I was happy knowing that I was starting a family with the man I would one day marry. He was the first person I told and he was cool about it. He was supportive but when his social security checks stopped coming he turned into a different person. He never made it to my appointments and he began ignoring me. He abandoned me. When our daughter was born he was on the phone, he heard her first cries but still didn't show up. He met her for the first time when she was three months old. At that time he told me he wanted to change and he wanted to be a family because I still loved him I took him back but I felt like he was ashamed to have a baby because he told me she wasn't allowed to come over to his house which hurt me. He was also very selfish didn't want to pay for anything but his own personal wants or needs. I finally had enough and left him. I still tried to co parent with him but he was only interested in having sex with me. I asked him to help me with summer clothes for our daughter and in exchange for his help he wanted to have sex with me. By that time I was in a new relationship and cheating is not in me so I refused. He never knew of the reason but he got so angry he showed up at my job called me names and told me to go prostitute myself for money for our daughter because he wasn't going to help me. I put him on child support. One year later I'm now engaged to the same man and we're expecting a baby this summer. My fiance has accepted my daughter as his own she acknowledges him as her dad and they have the most beautiful relationship that only a father and daughter could have but her biological father has popped up again asking to be taken off child support or to get custody of my daughter so he can be active duty in the Navy. The audacity! Problem is he's not being an adult about it. Showing up at our apartment unannounced with a very big dog, asking questions and demanding answers when we haven't seen him in a year. He also wants to spend time with her in our house! This is nuts I don't know what to do. My fiance is trying to be civilized but if this continues I can't keep him under control forever and I will side with him.