Jealous

Sorry ladies, I know this is going to sound pathetic and I embarassed to even bring it up - but I am struggling badly today.

Why am I jealous of the new woman? Why does it hurt knowing what I've been through with him its not healthy...

My head tells me he won't be faithful to her and that it won't last more than likely - but there is a part of me that wonders if it was me and that he will change for her and she will get the happy life he promised to me.

Like I said I know its pathetic and I shouldn't care guess my heart hasn't caught up to my head??

Has anyone had similar feelings or am I indeed going crazy?