Is it normal for you to feel disconnected after your heartbroken?

When I was young I could feel like I loved someone in a week. My first real boyfriend when I was 15 I liked for two years so I knew I loved him, or thought I did, the important thing is that whatever I felt for him i felt very strongly. When he broke up with me I think it was the hardest I ever cried in my life.

I had a couple of relationships after that that weren't too important romantically, one was with my best friend to this day, but he just ended up being my best friend soul mate.
The next relationship that had a real impact on me was with Josh. Oh my gosh, I loved him. He was my real and true first love. Deep and unconditional. When he left, well, I cried harder at 15 but with this break up I cried longer. I don't mean in one sitting, I cried every night for 5 or so months. After him is the longest time I was ever single since 15.

After that I felt disconnected with everyone I had a relationship with. To this day when I'm with someone, although I try my hardest to be with them mind, body and spirit, it doesn't really feel real. I always have the feeling like my happiness is fleeting, or that the rug under me could be pulled at any moment. Sometimes I even feel so far away that I don't even know the person sitting next to me.

I was so quick to feel strongly when I was young, but with every failed relationship I feel more and more disconnected from the person I'm with and even from the ability to love them.