Is this really new or you were already alone but distracted with others?
It is ok to feel alone. It is natural, and as long as you take the time to learn about yourself and what you really want and need, you'll learn and grow (even enjoy).
It won't be your last time, but it gets easier as you get older.
Cherish that your only priority is yourself (and your dog. f*k the cat :-p). It won't last.