The flame-haired actress - who plays Joan Holloway in the 60s-set TV show, which was recently renewed for a sixth season - claims the programme has "completely changed" her career and she doubts she will ever find a job she loves as much.
She said: "It's completely changed my career. Instead of people wondering who you are, you walk in and they say, 'I love your show'. It's a nice way to start an audition.
"I hate to think of it ever finishing. I have concerns about finding something I'm going to fall in love with as much."
However, Christina - who is married to actor Geoffrey Arend - is looking forward to other projects and spending some time with her husband.
She said: "I've got a couple of things lined up for the next break, and I hope to enjoy my home and husband."
Christina, 37, was "smitten" with Geoffrey when she first met him because of his sense of humour.
She told Britain's Glamour magazine: "It just became very obvious to me, I was smitten. He makes me laugh and he's my best friend and I would always rather be with him than not, so those are pretty good indications."