Fears of the Future

So I have an 11 month old. When she was 4 months old, we conceived a surprise blessing due in October. It took awhile, but I finally grew very excited about my baby boy. However, now I am absolutely terrified of the thought of raising two kids under 2 years old! The thought of it has started to bring panic attacks. They will be 14 months apart. I have a loving husband and some family and friends willing to help if they can, but the fears won't go away. What is some advice or encouragement from Mommies who have been in this position?