Loosing my identity

Do any other SAHM's ever go through phases where they feel like they have lost themselves?  I should preface this by saying that I love being a SAHM and feel so fortunate to be able to stay with L & R but there are times when I feel like I have lost myself.  Prior to having children, I was a clinical database builder and was making a nice income and moving up in the company.  Once I had my first child, I realized that I couldn't work full-time as it just wasn't for me.  Now though, they are getting older and need me less and less and I feel like I am just floating in space.  I don't think I will ever go back to work full-time but I'm going through a phase now where I would love to find a nice work from home part-time job.  I depend on my husband for all of our income and if I want to buy him something nice, I'm using "his" money to buy it.  He doesn't look at it this way but I do and I just get lost sometimes in it. 
I would just like something to bring in my own money.  My husband keeps telling me that I can work for him and help him to make more but that isn't the same to me.  He doesn't understand it and I just don't know how to explain it to him.