It almost sounds like you are one of those socialable people who just needs other people around, like you haven't before had to consider how you got to the position where you have friends.
I think you are over the first hurdle, as you want to be sociable, most people who struggle do so because they can't get out there.
While you are grieving for your relationship you will have strong emotions, that you cannot control and make the future look bleak. What you can control is your behaviour hence exercise and other simple activity being so important.
I looked at this recently, it made me think about how to form good relationships, by recognising that all personalities have little quirks, even if not actually a disordered.
www.mind.org.uk/information-support/typ ... -disorder/