In short, absolutely not! While you may read that "finding a co-founder" is a necessary idea out on the web, this is one of the greatest fallacies of what it takes to build a successful startup from the ground up, and bring your Idea to market.
In most cases, if you didn't start with one, you will find it very difficult to find a co-founder who truly shares your Vision, and your passion, for The Idea as fully as they need to...after the fact, you will only find this frustrating and it'll cost you potentially 50% of your equity to boot.
In our work with startups of all shapes and sizes (and their founders) for nearly 20 years, those that I've seen with two partners (co-founders) are also the ones most likely to implode, whether its over money (and who's carrying the financial load), expenditures, how to move forward, disagreements on the Vision for the long-haul, and divided passions. It will also impede your decision-making ability too, especially when this is your Vision you're pursuing...you need to remain in control of that, otherwise it can get diluted rapidly.
As others have said too, you do not need a management team to secure investment capital for a startup beyond your own. Any "smart money" investor realizes the challenges of building a successful startup / new business, and many early stage startups gain funding in part due to having a lean team, a great idea, great execution so far (this is CRITICAL by the way), and a clean cap table too.
So don't be discouraged at all, and carry on as you are, without troubling yourself with these kind of "golf thoughts", it'll only negatively impact your proverbial swing :-)
What you're doing now takes the right timing, the right idea, and enough (usually internal capital) to get to market and find some initial customer traction to prove that your idea has wings.
Then, the rest can take care of itself as you move forward in your journey. Onward and upward!
