Is this settling?

I don't know whether to end this relationship or not. Basically he's a lovely guy, treats me really well and is completely loyal and honest. The thing is, I don't feel all that physically attracted to him anymore and I don't feel all that intellectually stimulated. wit him...I know it's a really horrible thing to say but it's the way I feel. Basically I love him but don't think I'm in love with him anymore. The thing is, we've been together for 4 years and I'm 29, I want to settle down and have a family soon. He wants us to make a proper commitment. I'm just worried that feeling the way I am, I'll be setting myself up for disappointment later. Do you think I should end it now and find someone more compatible? Is this settling or should I stick with it and make a commitment? Thanks for your help