OP - please really really take this in - there is NO SUCH THING as a "natural mother".
No-one 100% loves devoting their entire waking and sleeping life to a new egotistical little creature who gives little, and needs the moon and back. No-One.
We have a love instinct and we love them, of course we do (even if for some it may take time to emerge, and that is fine). But it doesn't mean we have to love every minute of parenting, a lot of it is a big old slog.
It gets easier as they grow away from you and paradoxically grow into being able to relate to you instead of just demand from you.
Of course in the growing away process there are also enormous challenges and whatever age your children it is never going to be 100% bliss. In some phases (toddler, teen?) the bliss element is very limited and the slog element augmented!
If it helps mine are 8 and 5 at the moment and it is broadly speaking a really good time - I really enjoy it quite a lot. Though I can't stand them shrieking at each other ....
But there are lots of lovely moments. Last night I had a 30 min chat with my little girl. So lovely, at the end I was tearful at how pretty, funny, grown up and interesting a person she is.
The other day I pleaded with my little boy to PLEASE just get dressed without a fuss as I was not feeling well today. In the olden days that would have been lost on him. This time, he co-operated and said patting my arm "Oh dear mummy. Shall I make you a little get well card when I get home from school?".