It could be hormonal, it is worth considering and ruling out. When women go through the menopause, anxiety features a lot.
It is probably just the enormity of life and possibly the feeling that it's all going so well, am I going to lose everything?
If you have a peer support programme at work, use it. If not, speak to a doctor to put you in touch with a psychologist.
What I really want you to know is that you're not "sick" but you just need a small hand to understand how you're thinking.