Never had it, not in the sense of having someone say a partner and then a sudden abrupt separation.
Although I have contemplated changing relationship dynamics with loved ones in the face substantial life changes, and whilst concurrently living alone.
Being in contact with people I care for in some form is important to me, but I appreciate that everyone has their own lives to live and therefore physical proximity may not always be viable.
For the majority of people however, they live within communities of other individuals, and in proximity to wider clusters of people that can be contacted. Therefore engaging with others is within arms reach, however difficulty they may believe doing so actually is.
Regardless of others, being comfortable with yourself is something worth arriving at. You are the only person you can guarantee is going to be around for you, therefore enjoying those moments by yourself and turning them into something productive, and being mindful of the formation of crunch like relationships on others is worth pursuing.