Is he teething? Does he have a temp? I wouldn't suggest letting him CIO, he is still very young (not that I agree w. CIO at any age, but that's just me). He's only 7 months old and needs his mama right now, try to just soothe him, rock him and sing to him, walk back and forth and shhhh in his ear (that's what I did with my DD for hours on end). Some nights are going to be like this with a baby that age, it will get better I promise! Try a bunch of different things like that, you will find one that works and gets him to settle down w/o having to cry himself to sleep. Oh, another thing that works like magic with my DD is a soothing lullaby CD, do you have anything like that?