Lost confidence at work

I have been in the employee benefit business for over 20 years. I’ve managed to make a living that supported my 3 children and me after the death of their father. But somehow I’ve lost confidence and am afraid it is going to effect my ability to “land” new clients. Today I made a warm call to a business owner. While we spoke I felt like I jumbled my words and broke out in a sweat just talking over the phone! How will I handle the personal meeting?! My mind is imaging all my competitors and how much more tools, experience, back room support they have. I lost a client (and a boyfriend) earlier this year. I didn’t see it coming. I understand it has to do more with them than me but still it has managed to undermine my confidence. How do we hold our head up after loss?