Everyone will come and go from a company eventually, unless they die or the company shuts down. Although you work closely with these people, ultimately this is

Everyone will come and go from a company eventually, unless they die or the company shuts down. Although you work closely with these people, ultimately this is a transaction between yourself and the business and if you really have a good relationship with your colleagues, and they are good people, and they will understand and support you in your transition. But these feelings are normal!