Putting away the security blanket

My childhood sweetheart is my security blanket. We share a kid together so he is one of my oldest friends, and one of the people who knows me the best. I love how he is always happy to hear from me, and sad to see me go. I like how he always encourages me when I feel down, and tells me quite often how he thinks I could do anything. It is very stange to know that all of this is coming from someone that I had a very intimate relationship with. But over the years it has come to be so comforting. At this juncture, and for a very long time now we have been platonic friends. I stopped looking for us to get back together long ago, and got off of the rollercoaster we called our relationship while the getting was good. So for years, he has just been lucky to get any type of response from me. But we have so many memories and so many things in common that we keep up with each other like old pals. I realized that I may have settled for 2 dimensional relationships with guys that I did not share that type of bond with because I was still able to get that from him. He was the yardstick of which I would measure a potential suitor's manhood, and I know that wasn't fair. I am wondering if in order to truly step out there and have the whole shebang relationship that I want, will I have to give up my ego boosting security blanket? I mean our relationship raises eyebrows. People always think that we are attracted to one another, and I always have to explain it to guys that I date. But I can't imagine us not being friends.