We've just gone from 1 to 2... And I was also very nervous about it. There is a 3.5 year age gap, which helps - DS1 is pretty independent.
Adding a 2nd has been much easier than I thought it would be. I have been much more confident and easy going with DS2, and it's been a fantastic experience.

Going out has an added element - pram, nappy bag, bottles etc, but it's not going to be like this forever, it's only short term and I can't wait till both boys are running around playing together.