Anxiety over new relationship: help please, I really want to overcome it!?

I have met someone two months ago. I am in my early 40s and have not been in a long term relationship for a long time. I have indeed collected a series of disastrous relationships - mainly cos I prefer to finish a so-so relationship than carry it on just to have a partner. Now with him I feel really great! He makes me happy and I think I make him happy. He seems normal hurrah!! I think I have met a normal, down to earth, fun sensible man with a good heart and an intelligent mind. All is perfect. I stopped sleeping though! I am SSSOOO scared. I cannot stop thinking about him, and I am normally a rather calm and laid back woman! Realistically, if things didn't work it would not be the end of the world - we have known each other two months, I would get my life back as it was. So I don't know what I am scared of!

I want to enjoy this relationship because it is so much fun! We go see comedy, play music, to gigs, to watch live sport, dance, we do so much together in spite us both having full time demanding careers and being lone parents. I want to endure my anxiety hoping that I relax at some point, because I don't want this fear of I dont even know what to seep in and break this relationship. Any advice? How do I start sleeping? I am tempted to get to sleeping pills just to help me cope with this first scary new period of my life!! Anyone been there??