You can only carry the can so far.
If you started an organisation or business and the buck ultimately stops with you and no-one else, you need to make it a priority to find some friends to share the load. Find people who will make what you’re doing theirs as well as yours, own it and take responsibility for its continuation and success.
Ideally, you need more than one friend: as Clay Shirky points out in this excellent set of videos about network theory, three people in conversation is fundamentally different from two. If one side of a two-person conversation leaves, the conversation stops. With three people in the conversation (or more), people can leave and be replaced, and the conversation continues. In fact, every single participant can change, and it can still be the same conversation.
If you’re a free-lancer, and one day you can deliver your last piece of work, get paid, and close up shop, then you need friends for a different reason. But if you’re building something bigger than yourself – especially if it’s in service of a cause – you’ll soon have responsibility for other people’s work and salaries, and it will get old fast if you’re alone at the top.