Cold feet

I’m somewhat new to running my business and as things are getting more serious for me I’m starting to get cold feet. It’s very daunting seeing everything coming to life and just wanted to know how other people got over this? I have my own mobile detailing business that I’ve been running since I was 19, but it’s always been a very small business that I’ve mainly just done for family and friends or the odd client that would contact me through word of mouth. I’m turning 27 in a month and I’m now taking my business serious and have a full business plan done up, I have ad campaigns drafted up, a pricing structure in place and have everything thought out, I’m currently just waiting for spring to roll around (I’ve still got some last minute things to get done such as a website). But as we get closer and closer it’s starting to freak me out.