Someone once told me that when you take alcohol out of your life you need to put something else back in. Of course I thought it was just another one of those 'slogans', but for some of us it is very true. The many sayings and words of wisdom can really help us get through those early days of sobriety. It isn't easy to begin to learn how to live life without a drink in your hand. Sometimes even just trying to imagine it brings us to despair. You are certainly not alone in your thoughts and feelings in that regard. Determination alone is not necessarily enough when contemplating a new way of life that is inconceivable.
There is help out there in many ways. This forum, meetings, and other tools are at your disposal. You just need to take that first step and accept the help and support that is available.
In time the sense of loss will dissipate. You'll begin to find joy in other ways. Begin to replace the chaos with serenity, and the ego with humility, and discover a connection with others that a life of drinking can never achieve.
In years to come you may even find that your present fear of loosing your 'fun life' with alcohol is as laughable as it is irrational - yet that is hard, or even impossible, to see from where you are standing now.
Give yourself credit for taking the first steps on a path to sobriety, and acknowledge what you are feeling, yet keep on the path and reach out to others for all the help and support that is freely available.