It's OK! You can retain your existing email address for as long as you want :D
We recommend Google's free Gmail service as the best email solution in the marketplace today, and we recommend Google's paid Cloud G Suite service (which includes Gmail) for our business customers. Both solutions deliver better reliability, security, spam protection and synchronisation (between your devices) than any other product we have seen. Both are cloud-based services where your email is stored "in the cloud" (or on the internet if you prefer) with full security. This means you can check, send and receive your email from any device and it will always be up to date. Your also get built-in malware and spam protection which is even further enhanced if you use Google Chrome as your web browser.
You can have your cake and eat it too! When you switch to Gmail, you still retain your existing email address for as long as you want, it usually takes between one and two years to uncover all of the places you have used your current email address as a login. It takes nowhere near as long for you to advise your family, friends and business associates, but you do need plenty of time to change all of your login details.
Switching to the free Google Gmail service
Switching to Google Cloud G Suite for Business