Is it love or comfortability?

I’ve been in a relationship with this guy for almost 4 yrs now. We have lived together for 3. Things are comfortable. I can tell him anything. He’s AWLAYS been there for me. I can completely rely on him and trust him. The problem is, I just don’t have that “madly in love” feeling. I never have with him. Not even when we first started dating. Should I hold out for that special someone to sweep me off my feet? Do I settle for what I have just because it’s easy and comfortable?