Coming out later in life

I’m 29 and I’m so afraid to come out as bi because my family and BF are homophobic. When I see girls in a loving monogamous relationships with their little families it makes my heart ache. I know I’ve always been way more interested in females, my first crush was a girl and I got bullied in school for not liking boys, but I’m also terrified of coming out. My BF feels more like my friend and I’m trying to figure out how to tell him that while I love him I’m not in love with him in the way that I should be. And my parents & grandparents- I own a home and have a professional career so I don’t need them but I’m close with them and they’re aging and I’ll be taking care of them when the time comes so I don’t want them to disown me. My mom found lesbian literature when I was a teen and freaked.