confused do you think you are mourning the end of the relationship still, or is this part of your makeup, that you don't like your own company?
Have a think about what makes you tick and what you really want. This is your opportunity now to have an honest re evaluation of your life and goals.
I have always loved being alone and found being married quite smothering. I have also been on holiday totally alone for a week abroad which I loved so much, I go to the cinema, museums, restaurants, wherever I want on my own. Sometimes my mates get a bit cross with me asking why I didn't ask them along, but I do like to do stuff alone as well as with friends.
If you don't feel like this, there is no shame in it, we are all different, and you need to make plans to fill your life with whatever makes you happy. Do you have friends who you could do stuff with at the weekend? Just because they are married/coupled up doesn't mean they won't be up to do something fun an escape for a bit - they could be like I was, feeling all suffocated 
Just think of this as a phase of your life where you concentrate on yourself and DC and get to know yourself better rather than pouring all your energy into a partner.
I hope it all feels less stressful soon.