How Do You Know When It’s Time to Expand Your Startup Team?

I could use some advice.

My startup is off to a great start; traction is solid, customers are happy, and we’re growing steadily. But as we scale, the workload is getting out of hand. I’m managing everything myself right now, and it’s starting to take a toll.

I’m wondering if it’s time to hire, but I’m hesitant to make that leap too soon. What made you realize it was time to expand your team? 

Any lessons or tips would be super helpful. Thanks!