My crown doesn't feel loose but looks like its coming off , the tooth is visible slightly at the gum line in front and back, is this normal?

Perhaps: It may be that the margin where the crown and the tooth meet are simply visible above the gum line. This can happen if the dentist prepares the tooth that way or if your gums have receded since the crown was placed. This is more a cosmetic concern than a functional one. The other possibility is that you have decay around the margin, which is a real concern. I'd have a dentist look at it to be sure.

This is common: Sometimes there can be recession of your gums around a crown and the crown margin( the edges of the crown where it meets the tooth) can be exposed. In a front tooth this can be unsightly and you may want to have the crown replaced to look better. In a back tooth, this is not such a cosmetic problem. In both area this can cause sentisivity to cold that your dentist can treat.