No, do not create a new business. Just enter your business income as you normally do. When TurboTax asks if you have an EIN, answer Yes and enter the EIN. It's all one business.
Now that you have an EIN for your business, you should consider asking your other clients to use your EIN instead of your SSN, just to reduce the exposure of your SSN. You certainly should not give your SSN to any new clients.
