Feeling inadequate for motherhood

Does anyone else struggle with feelings of inadequacy in regards to motherhood? I find myself looking at my peers (I'm 28) who are having kids and I long for the experience of motherhood but I don't feel fit. I don't think I'd be a bad or even mediocre mother but for some strange reason I've always struggled with the idea of having my own children, even though I would like to. It's really strange and tough to deal with. Anyone have a similar experience? And if so, how did you work through it?

BTW I have a history of depression and anxiety.