It's almost impossible to successfully walk into a relationship wanting to change a person.
One thing I made up my mind about (thank God) when I was about 15 years old, I was going to marry a traditional Catholic no matter what. That was it. I was not going to be arguing with my in-laws about the Church, that was for sure. So I did.
Things aren't perfect all the time.

But I don't have a religious difference with him, which would have made everything 10000000000 times more difficult.
People that get into relationships with non-Catholics are in for a tremendous heartache. The first five to seven years of marriage, believe me, are a time of adjustment, and pain (in most cases.) Add the religious difference in there, and the throw-away attitude of most protestants towards marriage, and you have a failure.
I've been married 12 years, and with lots of prayers, we are doing great. Better than ever.
Advise from a veteran mother: Never ever marry a non-Catholic. Don't marry one even if they promise to convert! Marry them AFTER they convert, and never before, if you're intent on marrying a non-Catholic. There are enough problems in a Catholic marriage, that you don't want to add those kind of problems. It breaks up sooo many marriages, and Traditional Catholics should know better by now, that marrying a non-Catholic is a very bad idea.