Regret abortions and boyfriend has a child

Hi guys I have gotten pregnant with my current boyfriend three times . All of which I was ready to take the steps to being a mother . I was ready to sacrifice what I needed to in order to take care of that child . Each time I found out I was either 3 months or 4 months . I had an attachment to every moment . But when I told my parents they threatened to throw me out and when they sat down with my boyfriend to talk me into having an abortion, he said he didn’t support my decision to keep them . I didn’t care . But after time my mom would just pressure me more and more into getting the abortion until I couldn’t take the back forth anymore and I gave in . Now I’m 21 turning 22 (I got pregnant when I was 19 twice and 20 once) . Me and my boyfriends I’ve together , he daughter comes over to sleep over on weekends and it’s too much for me , when I see them together and him being such a good father to her . Then he ask me to do things with her and pretty much play like her other mother , and I can’t . All I think about is how it would’ve been with children of my own . If he supported me the way he supported the pregnancy with his daughter today . I’m here in my bathroom crying with them out in my living room watching cartoons . Every time I try to tell my boyfriend how I feel I feel like he takes it the wrong way like I don’t like the fact he has a daughter and that’s not it . It’s I want to have that same joy he gets when his daughter comes on the weekend , I got the joy when I found out I was pregnant each time , now I can’t have that . And I deeply regret it . How should I better explain to him my feelings and what should I do ?