I keep having this dream that my husband is going to leave me for a younger, prettier woman. The woman and place that it happens is different but the outcome is always the same, he leaves me and the kids

I guess I don't need to tell you - but - this is your underlying 'fear' speaking to you.  Perhaps you feel in adequate because of your age or size.  Perhaps you think that 'looks' and 'youth' are what matters most to your spouse.  I think that you need to speak to him and ask him ways in which you can enhance the emotional aspect of your marriage - as these dreams - suggest it is very lacking (on your part).