Tony you're the best *hugs*!I knew you could do it!
Now, please, take an equal amount of time (or more) that you spent thinking it would be difficult over the last week, and think about how nothing went wrong when you did do it. Think about every fear/concern you had prior to doing the interview, and match that up with what the reality was when you were in the interview. That way, when you fear something in the future you can refer back to this time and say to yourself, "I may be fearful now (of whatever), but I realize that when I do (whatever) nothing bad will actually happen because I feared things in the past and did them and nothing bad happened, so I don't need to be fearful". Use that to comfort yourself in the future. You've earned it. I hope that makes sense.