Selfish Boyfriend?

Cathy • Asexual and proud.
My boyfriend and I have been dating for 5 years and for these past 5 years, I've always felt like he's not interested in anything that I say. 
When we talk on the phone or go on dates/hang out, he talks 80% of the time and I talk 20% of the time. 
When I do talk, he usually cuts me off because he can relate and talk about the same topic about himself or he completely doesn't hear me/ignores me and gets distracted so he talks about something else. 
Sometimes I just feel like he doesn't really care about me or put importance in anything that I say. 
Maybe it's my fault- maybe I'm just really boring... But why would he date me if he thinks that way? 
I've already talked to him about this multiple times and he still doesn't do anything or fix anything about it. Please help me... I just feel so unimportant.