Why isn’t he attached to me?

I have a 5 year old boy from a previous relationship and I have a 14 month old boy with my husband. My 5 year old has always been a HUGE mommas boy. He was always extremely attached. I was a single mom for the first year of his life so of course I had to work a lot. And even though he was in daycare 5 days a week, we have a very close bond, especially as a baby and toddler. Don’t get me wrong, he absolutely adores my husband and my husband claims him as his own, but it’s just not the same. My 14 month old on the other hand, is completely obsessed with his Daddy. Which I understand and it’s not that I don’t like that. It just makes me sad that he doesn’t have the bond that I have with my oldest son. It’s weird to me too because I’ve been a sahm since he was born and his dad works long hours. He’s with me and his big bubba all the time, unlike how it was with my oldest as a baby. But he wants his Daddy for everything, it’s really starting to hurt my feelings. He doesn’t cry when I leave, but throws a huge tantrum when his dad does, he doesn’t want me when he’s sad or hurt if my husbands home, he will hit me and pull my hair but won’t do it to his daddy lol. I know that hitting and pulling hair is normal for his age, but why only to me!? Lol. It just really bums me out. I guess I’m just used to my oldest wanting me for everything.